313 articles trouvés pour ce sujet.
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Espaces vectoriels |
2002-08-18 |
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Bacar pose la question : Comment montrer que trois (ou plus que trois) sous espaces vectoriels sont en somme directe. Claude Tardif lui répond. |
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A scenario for a linear equation |
2021-01-19 |
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raven pose la question : I have to create a scenario for the following equation y=-1x+45
and then find what each part of the equation represents Penny Nom lui répond. |
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Two equations with fractions |
2020-10-22 |
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mia pose la question : I am supposed to look for x and y. my teacher didn't explain very well. please help : ((
2x - y = 5
x/4 + y/3= 2 Penny Nom lui répond. |
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Simultaneous equations |
2020-09-05 |
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Paa pose la question : a+b=8
a+c=13
b+d=8
c-d=6
find the value of each letter Penny Nom lui répond. |
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A word problem involving linear equations |
2020-06-22 |
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Allie pose la question : The length of a rectangular swimming pool is p m and its width is q m. Its given tht the length of the swimming pool is twice its with. if the perimeter of the swimming pool is 150 m, find the values of p and q
this is in the chapter linear equations Penny Nom lui répond. |
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The substitution method |
2020-06-10 |
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Hardebolar pose la question : simultaneous equation by substitution method
.a-b=2/3 a+b=1 2/3 p lui répond. |
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A rectangular garde |
2020-04-10 |
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Denise pose la question : In a rectangular garden a person says "if I made that bed 2 feet wider and 3 feet longer it
Would have been 64 sq,ft bigger. But if it had been 3 feet wider and two feet longer
It would have been 68 sq.ft bigger.
What is the length and width of the garden bed? Penny Nom lui répond. |
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Setting up a linear equation |
2020-04-10 |
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Jessie pose la question : Michaela and Aleah play on the same basketball team. In one game, Michaela scored
one fifth of the teams points and Aleah scored one tenth of the teams points. Together,
they scored a total of 42 points. How many points did the team score?
I can't figure out how to put together the equation with the given variables. I have to show the work and I also need to know how to make
that kind of equation. Thanks! Penny Nom lui répond. |
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A linear system |
2020-04-02 |
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Dadzie pose la question : x+s=8→1
y+x=13→2
y-p=6→3
s+p=8→4 Penny Nom lui répond. |
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The equation of a line |
2020-01-05 |
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coco pose la question : Good afternoon
If relationship between total cost and the number of units made it linear ,and if costs increases by 7$ for each additional unit made ,and if the total cost of 10 units is 180$ .
Find the equation of the relationship b/n total cost (Y) & number of unit made (x). Penny Nom lui répond. |
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Simultaneous equations |
2019-10-16 |
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deepak pose la question : This is too complicated please help me
8/x - 10/y = 1 and x+y=9 Penny Nom lui répond. |
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Two power generators |
2019-06-07 |
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A student pose la question : At 100% efficiency two generators would produce 750 MW of power. At efficiencies of 65% and 75%, they produce 530 MW. At 100% efficiency, what power would each produce? Harley Weston lui répond. |
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Two linear equations with a fraction |
2019-04-26 |
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Asha pose la question : 2x=-3y …1
x-2+-4/3(y+1) ...2
note: … is equation Harley Weston lui répond. |
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A linear equation |
2019-02-11 |
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Nick pose la question : What's a linear equation? Penny Nom lui répond. |
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Simultaneous equations with fractions |
2018-12-14 |
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zaheer pose la question : solve simultaneous equations and give answer in fractional form
3x - 2 = 4y +5/3
y + 7 = 2x + 4
would really appreciate some help on this please Penny Nom lui répond. |
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Linear feet and cubic feet |
2018-07-16 |
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Dave pose la question : How do I convert: 1 foot wide x 15 inches high x 19 inches deep
We are trying to figure out how to convert the linear footage into cubic footage
the above are the figures represent just 1 linear feet of several thousand
Any thing helps,
Thanks in advance
Dave Penny Nom lui répond. |
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Simultaneous equations with fractions |
2017-09-09 |
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Farah pose la question : Hi, my name is Farah. I hope you can help me with this question . X/2 + g/5= 3 and 2g - f = 10 Penny Nom lui répond. |
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A pair of linear inequalities |
2017-08-08 |
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Hempstone pose la question : Solve the inequalities 3x-5<2x+5>4x+9 Penny Nom lui répond. |
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Catherine, Molly and Tom |
2017-07-19 |
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liezel pose la question : what is the answer of this problem, If Catherine and molly has 320pesos altogether, Molly and tom have 360 in all. Tom and Catherine have 240pesos altogether.How much does each of them have? Penny Nom lui répond. |
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Simultaneous equations with fractions |
2017-06-02 |
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Jamal pose la question : 1/x + 1/y =5 and 1/y - 1/x =-1 Penny Nom lui répond. |
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Five equations |
2017-01-16 |
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Muhammed pose la question : A x 4 = E
B ÷ 4 = E
C + 4 = E
D - 4 = E
___________
& A + B + C + D = 100
what is the value of E Penny Nom lui répond. |
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Simultaneous equations with fractions |
2016-12-21 |
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Kimi pose la question : I am stuck on this,can someone please help me????
1/2x+1/3y=11
8x+2/5y=102
Can someone please explain how to solve questions like these??
Or else I will never learn...
Thank you Penny Nom lui répond. |
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Simultaneous equations |
2016-11-25 |
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Rohan pose la question : x-2/3 + y - 1/4 = 13/12
2-x/2 + 3 + y/3 = 11/6 Penny Nom lui répond. |
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A linear relationship |
2016-10-16 |
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Bianca pose la question : x represents the number of hours since 8am. y represents the number of children the school nurse has seen during the school day. The nurse has seen 3 children by 8am and 27 children by noon.
How many children has the nurse seen at 2pm?
If the nurse has seen 18 children, what time is it? Penny Nom lui répond. |
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The length of stock on a roll |
2016-09-23 |
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Ken pose la question : I have a roll that is 13.5 inches wide ( OD) , and is wound on a 3 inch core. the thickness of the material is 3.5 thick.
Do you know of a formula that can calculate the linear feet on that roll?? Harley Weston lui répond. |
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The dimensions of a rectangle |
2016-07-25 |
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Krunox pose la question : A rectangle is twice as long as it is wide. Its perimeter (the sum of the lengths of its sides) is 60 cm. Find its length and width. Penny Nom lui répond. |
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The temperature inside and outside a greenhouse |
2016-07-22 |
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Mehzad pose la question : Every day, the temperature in a greenhouse is at its low temperature, 70 degrees Fahrenheit, at 2 a.m. and at its high temperature, 84 degrees Fahrenheit, at 2pm. Its temperature increases linearly between 2 am and 2pm , and decreases linearly from 2 pm and to 2am. The outside temperature follows the same linear patterns, but has a low temperature of 60 degrees Fahrenheit at 2 am and a high temperature of 78 degrees Fahrenheit at 2 pm. At which of the following times will the temperature inside and outside the greenhouse be the same?
a) 8:00 am
b) 12:00 noon
c) 4:00 pm
d) The two temperatures will never be the same Penny Nom lui répond. |
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Two equations with fractions |
2016-07-22 |
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kanesh pose la question : p/2+q/3=3
p/4+2q/3=3 Penny Nom lui répond. |
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Simultaneous equations |
2016-06-25 |
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sena pose la question : 2x/3+3y/2=-1
4x-5y=22
simultaneous equation Penny Nom lui répond. |
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A pair of equations with fractions |
2016-05-11 |
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tiya pose la question : hello, i want to know how to solve this question.
m/6+2n/3=6
-m/10=2n/5=2 Penny Nom lui répond. |
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Solve for x and y |
2016-02-27 |
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ntshidi pose la question : Y=1/2x+4and1/4x-6 Penny Nom lui répond. |
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Two equations in two unknowns |
2016-02-13 |
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Anumba pose la question : 4x + 2y = 4
7x - y = -11 Penny Nom lui répond. |
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A system of linear equations |
2016-01-24 |
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kareem pose la question : my name is kareem
and i am a student i have a math puzzle and i tried to solved it but it always have same mistake
x-y=9
x+z=12
z-n=14
y+n=2 Penny Nom lui répond. |
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Two transport companies |
2016-01-06 |
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Brynleigh pose la question : The Sugar Sweet Company will choose from two companies to transport its sugar
to market. The first company charges $5096 to rent trucks plus an additional fee of
$200.75 for each ton of sugar. The second company charges $5500
to rent trucks plus an additional fee of $175.50 for each ton of sugar.
For what amount of sugar do the two companies charge the same?
What is the cost when the two companies charge the same? Penny Nom lui répond. |
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A graph of the water level of a river |
2016-01-05 |
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emoni pose la question : Suppose that the water level of a river is 34 feet and that it is receding at a rate of 0.5 foot per day. Penny Nom lui répond. |
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Constructing simultaneous linear equations |
2015-12-28 |
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Deborah pose la question : Linda thinks of a two-digit number. The sum of the digits is 8. If she reverses the digits, the new number is 36 greater than her original number. What was Linda's original number?
Thank you! Penny Nom lui répond. |
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Linear equations in two variables |
2015-12-13 |
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priya pose la question : I have problem in solving these equations please help me today itself very urgent:
I)2x+y=y
II)pie*x+y=9 Penny Nom lui répond. |
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The method of elimination |
2015-05-01 |
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oreanna pose la question :
Question from oreanna, a student:
How do u solve 2x+9y=3
7x-4y=-25 in elimination Penny Nom lui répond. |
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Two equations with fractions |
2015-02-26 |
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Pulane pose la question : Hi math centre I've been trying to solve these equations for days now please help
(6/x)-(1/y)=4
(9/x)+1=(-2/y)
Please help me solve them simultaneously
Thank you Penny Nom lui répond. |
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Two equations |
2015-02-16 |
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nigel pose la question : 2x+1/2y=1
6x-3/2y=21 Penny Nom lui répond. |
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1999 equations in 1999 unknowns |
2014-11-28 |
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Subrahmanya pose la question : Solve the following system of 1999 equations in 1999 unknowns :
x1+x2+x3=0, x2+x3+x4=0……., x1997+x1998+x1999=0,
x1998+x1999+x1=0, x1999+x1+x2=0.
(in x1,x2,...................,x1999 the numbers 1,2,.............,1999 are subscripts) Penny Nom lui répond. |
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Two quadratic equations |
2014-11-20 |
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rajesh pose la question : Sir,
I would like to discuss on question-
-Find the value of variable X and Y, equations are
X2+Y2+2XY=25
X2+Y2-2XY=1
Sir, my point is equation looks not so easy.My opinion is there many
(more than 4)value possible for both X and Y.
Kindly help me.
Waiting for your response.
regards,
rajesh Penny Nom lui répond. |
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A linear system |
2014-10-14 |
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pheter pose la question : 4/x - 1/y = 3 .... equation (1)
6/x - 2/y = 5 .... equation (2) Penny Nom lui répond. |
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Two equations in x and y |
2014-09-25 |
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seyilogo pose la question : solve y=2x - 3 and (4x - 2y) / x + y = 1 simultaneously Harley Weston lui répond. |
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Two equations in two variables |
2014-09-18 |
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Susan pose la question : (28x + 36y) - [20000 - .75(28x + 36y) + 60000] = 5000
x + y = 10000
solving two equations involving variables Penny Nom lui répond. |
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Three collinear points |
2014-08-28 |
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jhanavi pose la question : p,q,r are three collinear points.p and q are(3,4) and (7,7) respectively and PR is equal to 10 units.find coordinates of R Penny Nom lui répond. |
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The method of elimination |
2014-07-05 |
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leo pose la question : please explain how can i solve this problem
3x-6y=-38
6x-9y=44
using elimination and simultaneous method thank you :) Penny Nom lui répond. |
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Simultaneous equations |
2014-06-20 |
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rana pose la question : solve the simultaneous equations
a)3x=7y
12y=5x-1 Penny Nom lui répond. |
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Two regression lines |
2014-06-14 |
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catherine pose la question : Given a set of data values ,we can get two regression lines .Explain. Robert Dawson and Penny Nom lui répond. |
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A trig problem |
2014-04-25 |
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srishti pose la question : Consider the points P= (-sin(a-b),-cosa), Q=(cos(a-b),sina), R=(cos(a-b+c),sin(a-c), where 0 Chris Fisher lui répond. |
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Simultaneous equations with fractions |
2014-04-19 |
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Maryam pose la question : I looked at your example of simultaneous equations with fractions and applied it to my question from an educate exam papers but I couldn't get it to work. The question is:
x/8 - y = -5/2
3x + y/3 = 13 Penny Nom lui répond. |
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Two nonlinear equations |
2014-01-26 |
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Naryn pose la question : (1÷x) + (1÷y) = (7÷12)
xy = 12 Penny Nom lui répond. |
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A linear equation |
2013-12-26 |
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khushboo pose la question : A farmer sowed wheat and paddy in two fields of total area 5000 sq.m. Write a linear equation and draw a graph to represent the same? Penny Nom lui répond. |
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How do I graph y=-2x-1? |
2013-12-07 |
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cindy pose la question : How do I graph y=-2x-1? Penny Nom lui répond. |
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A line through (5, 1) |
2013-10-08 |
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allison pose la question : find an equation in standard form for line passing through point (5,1) and perpendicular to line x=4 Penny Nom lui répond. |
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A system of equations |
2013-08-13 |
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Nina pose la question : 3x-2y=8
-x+3y=5
What is the solution of the system of equations Penny Nom lui répond. |
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4 linear equations with 3 unknowns |
2013-04-12 |
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Marian pose la question : how to solve for 3 unknowns in 4 simultaneous equations Penny Nom lui répond. |
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A linear programming problem |
2013-02-27 |
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Kelley pose la question : A manufacturer of skis produces two types: downhill and cross-country. Use the following table to determine how many of each kind of ski should be produced to achieve a maximum profit. What is the maximum profit? What would the maximum profit be if the time available for manufacturing is increased to 48 hours.
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Downhill |
Cross-country |
time available |
manufacturing time per ski |
2 hrs |
1 hr |
40 hr |
finishing time per ski |
1 hr |
1 hr |
32 hr |
profit per ski |
$70 |
$50 |
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Penny Nom lui répond. |
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A geometry word problem |
2013-01-24 |
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Matthew pose la question : "G", "A" and "B" are collinear. "A" is between "G" and "B". "GA" Is 14 less than 3 times "AB". "GB"=46 Find "GA"
How would you solve this? Penny Nom lui répond. |
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A word problem involving a fraction |
2012-10-12 |
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Derrick pose la question : If the numerator and denominator of a fraction are both decreased by 1 the fraction becomes 2/3. If the numerator and denominator are both increased by 1 the fraction will be 3/4. Find the original fraction. How to do? Penny Nom lui répond. |
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A problem that yields a linear equation |
2012-10-07 |
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Eshraj pose la question : one fourth of a whole number is three more than one fifth of the next whole number.find the whole number Penny Nom lui répond. |
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Row echelon form |
2012-09-05 |
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Jennifer pose la question : Hello, my name is Jennifer. I am a 12th grader in Pre-Calculus and I was wondering if you may help me with Row Echelon Form.
x + 2y - 3z = -5
-2x - 4y - 6z = 10
3x + 7y - 2z = -13 Penny Nom lui répond. |
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Problem solving |
2012-08-15 |
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Sugavanas pose la question : If length of a rectangle exceeds its width by 5 m. if the width is increased by 1m and the length is decreased by 2 m, the area of the new rectangle is4 sq m less than the area of the original rectangle. Find the dimensions of the original rectangle. Penny Nom lui répond. |
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John's electronic store |
2012-07-25 |
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Jora pose la question : Electronic Store
John opened an electronic store in December. During his first month,
He sold 10 LCD TVs and 20 Plasma TVs. His income during that
month was $12800. In January, he sold 25 LCD TVs and 40 Plasma
TVs for an income of $27600.
In February he projects to sell 30 LCD TVs and 50 Plasma TVs.
If John expenses are $28900 in February, how much money will he
have after paying the expenses? Penny Nom lui répond. |
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2x+underroot2=3x-4-3underroot2 |
2012-07-09 |
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Eshraj pose la question : 2x+underroot2=3x-4-3underroot2 Penny Nom lui répond. |
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The equation of a line |
2012-03-26 |
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Danielle pose la question : Hello, could you help me figure out what the equation of the line is in the form of Ax+By=C with the points (-2,0) and (0,3)?
Thank You! Penny Nom lui répond. |
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Four apples and two oranges cost Rs. 30... |
2012-01-13 |
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nasr pose la question : Four apples and two oranges cost Rs. 30, and one apple and 3 oranges costs Rs.15.How much does each apple and each oranges cost? Harley Weston lui répond. |
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Augmented matrix |
2011-12-14 |
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Britney pose la question : Write Augmented matrix and use row reduction to solve.
I need major help with this problem! Tomorrow is my semester test and I have no idea how to do this.
2x+5y=8
y-x=10 Robert Dawson lui répond. |
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Linear equations |
2011-10-06 |
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Hannah pose la question : I am confused about a question on my homework, here is an example on what I need to do:
You own a sightseeing boat tour. Kids' admission costs $5, adults' admission costs $8.
During that day you get (made-up number) $521 with 71 admissions.
How many of each passenger boarded?
I tried something like
5x + 8y = 521
x + y = 71
But, I still don't understand how to solve it! Help? Penny Nom lui répond. |
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An equation in the form Ax+By=C |
2011-07-28 |
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Mike pose la question : I need to write an equation in the form Ax+By=C
The points I was given are (5,0) and (-3,5)
I know how to find the slope I got -5/8 and wrote it out as y=(-5/8)x+b however I'm not quite sure where to go from here.
Any help would be greatly appreciated. Penny Nom lui répond. |
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A linear equation with fractions |
2011-07-13 |
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Simon pose la question : I would like to ask if you would be able to explain : linear equation: 2 1/2 (X-1) - x+3 /3 = 4 , the first step shows multiplying by 2 then multiplying by 3. etc. What I don't understand is where the 2 in multiplying by 2 comes from? ( the three is pretty obvious being x+3 /3 (to get rid of the divided by) ) .
Thanks for your help. Penny Nom lui répond. |
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Linear inequalities |
2011-03-25 |
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Alice pose la question : OK. I'm in algebra 1 and the linear inequality is
y<2x-1
y>2
I don't completely know how to graph y>2 and I'm getting really frustrated
Please help me in any way possible!
Thank You! Penny Nom lui répond. |
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What is the speed of each car? |
2010-11-04 |
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Jennifer pose la question : two cars are 420 miles apart and traveling towards each other along the same road. They meet in 3.5 hours. One car is traveling 15mph slower than the other. What is the speed of each car?
This must be solved using a system of equation, I have no idea? Stephen La Rocque lui répond. |
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An exponential equation |
2010-10-19 |
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Sandi pose la question :
Question from sandi, a student:
I have several questions similar to this one and was wondering if you could walk me through this one. I'm totally lost on how to do it.
Paramecia reproduce by splitting in two. In a laboratory flask, a colony of paramecia had an initial population of 500. Each day, the population of the paramecia was counted. The results are as listed.
Time (in days)------Population
0-----------------------500
1-----------------------600
2-----------------------720
3-----------------------864
4----------------------1037
5---------------------1244
6---------------------1493
7----------------------1792
8---------------------2150
1.)Using graphing calculator make a scatter plot of the data in table.
I think I did this part right I set my window at Xmin=0 Xmax=10 Xscl=1 Ymin=0 Ymax=2500 Yscl=100 Xres=1
2.) Determine an exponential equation to represent the population as a function of time without using a graphing calculator.I have no clue how to do this.
3.)Suppose the flask and food supply is large enough to support the trend of the population growth. Estimate the population of the colony when the time is 10 days. Penny Nom lui répond. |
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A linear system |
2010-10-15 |
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Sandy pose la question : HARD!! algebra (Linear Systems) question?
An Airplane cruises at 120km/h in still air. One day, when the wind was blowing steady from the west, the airplane travelled west (flying into the wind) and landed at its desination after 1.5h. The airplane's return trip (flying with the wind) was only 1.0 h long. On both legs, the airplane travelled at its cruising speed. (meausred with respect to the air surrounding the airplane).
Part A
Write a System of equations that would allow you to determine the speed of the wind blowing that day and the distance travelled each way
Part B
When solving the system of equations graphically, what equations would you enter into the equation editior (to make graphs on your calculator)
Part C
Indicate what the X and the Y represent Stephen La Rocque lui répond. |
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A strip of land |
2010-09-15 |
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Walter pose la question : How many linear feet of strip of land 15 feet wide does it take to make 1 acre? Penny Nom lui répond. |
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A linear relationship |
2010-06-22 |
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Laura pose la question : The monthly cost of driving a car depends on the number of miles driven. Lynn found that in May it cost her $300 to drive 480 miles and in June it cost her $460 to drive 800 miles.
Question: Express the monthly cost C as a function of the distance driven d, assuming that a linear relationship gives a suitable model. Robert Dawson lui répond. |
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4 > -3m-7 >= 2 |
2010-06-05 |
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pamela pose la question : The question is
4>-3m-7>=2 Penny Nom lui répond. |
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x/a +y /b =a+b : x/a^2+ y/b^2 =2 |
2010-05-30 |
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smithu pose la question : x/a +y /b =a+b : x/a2+ y/b2 =2 solve by using elimination method ,
cross multiplication, substitution method Penny Nom lui répond. |
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Graphing a linear inequality |
2010-05-26 |
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Valeie pose la question : When graphing a linear inequality, how do you know if the inequality represents the area above the line. Penny Nom lui répond. |
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A system of equations |
2010-03-30 |
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samantha pose la question : the equations of two lines are 6x-y=4 and y=4x +2.what is the value of x in the solution for this system of equations? Penny Nom lui répond. |
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The sides of a 30-60-90 triangle |
2010-03-29 |
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maris pose la question : Find the sides of a 30-60-90 triangle whose perimeter is 6. The solution must use systems of equations using 3 variables. Penny Nom lui répond. |
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A quadratic equation |
2010-03-15 |
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rachelle pose la question : under certain condition, it is found that the cost of operating an automobile as a
function of speed is approximated by a quadratic equation. use the data shown
below to find the function. then use the function to determine the cost of operating
the automobile at 60mph.
speed
(in miles per hour) |
operating cost
per mile(in cents) |
10 |
22 |
20 |
20 |
50 |
20 |
Penny Nom lui répond. |
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The line joining (3,4) and (-5,-6) |
2010-03-06 |
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Patric pose la question : Find the condition that the point (x,y) may lie on the line joining the points
(3,4) and (-5,-6) Penny Nom lui répond. |
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A linear relationship |
2010-02-24 |
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Mel pose la question : This table shows the linear relationship between an aeroplane's height (above sea level) and the outside air temperature.
h (cm) |
120 |
340 |
480 |
600 |
1040 |
T (degrees C) |
14.28 |
12.96 |
12.12 |
11.4 |
8.76 |
Find the gradient and vertical intercept of the function. Write the formula for T. Penny Nom lui répond. |
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Substitution method |
2010-02-17 |
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Melodie pose la question : 7x - 4y = -10
4y= x-2 Tyler Wood lui répond. |
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Substitution |
2010-02-14 |
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Izayah pose la question : what is 3 ways to find the meeting point of y=2x+4 and 3x+y=7
by making 2 table and using a graph Stephen La Rocque lui répond. |
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Linear growth |
2010-01-27 |
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S. pose la question : I. Linear Growth:
Suppose that the town has a fixed increase in population growth number of population increase each year.
Choose the amount of population growth each year = 200
(Hint: Choose a whole number for your growth rate, rather than a percent.)
a) Fill in the following chart:
Year (t) Population (P)
t = 0
(2010) 1000
t = 1
(2011) 1000+200=1200
t = 2
(2012) 1000+400=1400
t = 3
(2013) 1000+600=1600
b) Find a linear equation in the form P = mt + b (y = mx + b), which gives the population, P, t years from 2010.
. . .
Melanie Tyrer lui répond. |
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A linear equation with the variable on both sides |
2010-01-16 |
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dog pose la question : 4x-9=7x+12 Penny Nom lui répond. |
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A linear equation with fractions |
2009-12-31 |
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Michelle pose la question : How would I solve: (-2)(-1/2x + 5) = (-2)(8)? Penny Nom lui répond. |
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Linear programming using the Simplex Method |
2009-12-28 |
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William pose la question : A gold processor has two sources of gold ore, source A and source B. In order to keep his plant running,
at least three tons of ore must be processed each day. Ore from source A costs $20 per ton to
process, and ore from source B costs $10 per ton to process. Costs must be kept to less than $80 per day.
Moreover, Federal Regulations require that the amount of ore from source B cannot exceed twice the
amount of ore from source A. If ore from source A yields 2 oz. of gold per ton, and ore from source B
yields 3 oz. of gold per ton, how many tons of ore from both sources must be processed each day to
maximize the amount of gold extracted subject to the above constraints?
I need a linear programming solution or algorithm of the simplex method solution.
Not a graphical solution. Thanks. Janice Cotcher lui répond. |
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Two non zero vectors |
2009-10-27 |
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Nazrul pose la question : Given that a and b are two non zero vectors and ma+nb=0 where m and n are two scalars. How can I prove that m=n=0. Robert Dawson lui répond. |
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A word problem |
2009-10-24 |
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Ryan pose la question : Two times one number plus 7 times another number is equal to 17. the first number plus the second number is equal to 25. What are the two numbers? Please Help! Penny Nom lui répond. |
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A linear system |
2009-10-20 |
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marissa pose la question : Solve this linear system
2x-y=5
3x+y=-9 Penny Nom lui répond. |
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$6.25 in nickels quaters and dimes |
2009-10-10 |
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miriam pose la question : a piggy bank contains $ 6.25 in nickles quaters and dimes.
there are 65 coins all together and there are four times as many nickles as quaters
find the number of coins of each kind Penny Nom lui répond. |
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Two rectangles |
2009-10-08 |
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Lillian pose la question : A rectangle is 5cm longer than twice its width.
The width of another rectangle is 3cm less
than the width of the first rectangle and its length is 6cm more than 3 times its
width. If the perimeters are equal, find the dimensions of both rectangles Penny Nom lui répond. |
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Elimination method |
2009-10-08 |
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Kenty pose la question : How do I solve this problem using the elimination method?
3x-7y=0
6x+4y=0
I am not sure how so if someone can show me a similar problem (instead of
solving this one for me) that would be fantastic. Penny Nom lui répond. |
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The method of substitution |
2009-09-17 |
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laura pose la question : ok! i really need help with this question plz help!!
x= - 4y +5
x+2y = 7 Penny Nom lui répond. |
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10x-8 /3 =6x+24 /5 |
2009-09-16 |
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Heidi pose la question : 10x-8 /3 =6x+24 /5.....I know the answer is 7/2 but how do I get there? Penny Nom lui répond. |
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Simultaneous equations |
2009-08-28 |
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onias pose la question : solve 3/a - 2/b = 1/2 , 5/a + 3/b = 29/12 Robert Dawson lui répond. |
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y=2x+1 and y=2x-1 |
2009-08-28 |
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MARICELA pose la question : Need help of how to work this problems
y=2x+1 and y=2x-1
First of all what is the difference?
Second I think is easy just to work with the X y with the line in the middle
but how do you get the numbers for each side. Penny Nom lui répond. |
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Linear equations |
2009-08-23 |
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shwetha pose la question : The length of a rectangle is greater than the breadth by 18 cm. If both length and breadth are increased by 6 cm then area increases by 168 cm square. Find the length and breadth of the rectangle. Stephen La Rocque lui répond. |
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Graph 2x-3y+15=0 |
2009-08-20 |
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Diem pose la question : Graph 2x-3y+15=0 Leeanne Boehm lui répond. |
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Two equations in two unknowns |
2009-07-30 |
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Alicia pose la question : I need help with the following equation please show me the steps to complete so that I will know how to do this my self.
2x-y=2 5x+y=5 Thanks for the help Penny Nom lui répond. |
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Finding the Line Joining Perpendicular Feet |
2009-07-16 |
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mukulu pose la question : Please help I've been tryng to search in your data but i failed to get the solution Find the equation of a straight line joining the feet of the perpendiculars drawn from the point A(1,1) to the line 3x-3y-4= 0 and 3x+y-6=0. Janice Cotcher lui répond. |
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Two equations |
2009-05-31 |
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tony pose la question : y = 1.2x - 32.7,
y = -0.7x + 46.15
can you please solve this for me? i am not able to figure it out... thank you
tony Penny Nom lui répond. |
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(x + 1) / 3 + (x + 2) / 7 = 2 |
2009-05-22 |
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MzDonna pose la question : Question from MzDonna, a parent:
We can't seem to get an answer for this problem:
X + 1 X + 2
_____ + _____ = 2
3 7
The book gives the answer as 10 ; But, we struck. Please help us.
___
21
Thanks in advance for your assistance. Stephen La Rocque lui répond. |
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Two equations |
2009-05-18 |
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Bob pose la question : solve the system:
x/2 - 2y= -8
3x + 2/3y= -10 Stephen La Rocque lui répond. |
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Finding an Array to an Integer Linear Programming Problem |
2009-05-12 |
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Debbie pose la question : how to make an array for 3 box of juice for 25 students and 2 teacher. 1 pack of juices
hols 3boxes the answer is 9 packages but how do you make array for this Janice Cotcher lui répond. |
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Solve -1<5-2x<10 for x |
2009-05-12 |
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Helen pose la question : solve the following inequality for x
-1<5-2x<10 Te less then sign by the one, should be less then or equal to. Stephen La Rocque and Penny Nom lui répond. |
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Stairway construction |
2009-05-02 |
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Olivia pose la question : Hi, I'm Olivia and I'm in 8th grade studying algebra 1. I'm having some trouble with my math project. It has to do with rules of stairway construction. It says that there are two generally accepted rules to building stairs.
Rule 1: x+y=43 and x+y=46 (cm)
Rule 2: 2y+x=61 and 2y+x=64 (y is the riser and x is the tread length)
I cant figure out how to graph them...it says they're supposed to intersect to make a square which is like the safety zone for building stairs (the stairs' rise and tread lengths are plotted as points) any points outside of that square are considered unsafe.
Did i explain it ok? Thanks for your help.
--olivia Penny Nom lui répond. |
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An infinite number of solutions |
2009-03-24 |
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Sean pose la question : this is a linear equations problem;
first:
3535.5 + Fbd (.866) + Fbc (.5) - Fab (.5) = 0
and
-3535.5 - Fab (.866) - Fbc (.5) - Fbd (.5) = 0 Harley Weston lui répond. |
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A dead fly is stuck to a belt that passes over two pulleys |
2009-03-21 |
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Jules pose la question : A dead fly is stuck to a belt that passes over two pulleys 6 inches and 8
inches in radius. Assuming no slippage,how fast is the fly moving when
the large pulley (8 inches) makes 21 revolutions per second ? How many
revolutions per second does the small pulley make ?
How long will it take the dead fly to travel 1 mile ? Penny Nom lui répond. |
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A linear system |
2009-03-13 |
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Rasanga pose la question : Use the row echelon form of the augmented matrix to solve the following linear system.
X1+2X2+X4=6
X3+6X4=7
X5=1 Harley Weston lui répond. |
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Find an expression for the nth term |
2009-02-20 |
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Dawn pose la question : Find an expression for the nth term:
x= 1 2 3 4...n
y=11 8 5 2...?
I think it's a linear relation but don't know the equation that goes with it. Stephen La Rocque lui répond. |
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Linear systems |
2009-02-20 |
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Rose pose la question : I have been having trouble trying to figure out these three math problems , I need help breaking them down so I could understand them better please help.
1. x = 7 - x
2 x - y + 8
2. 8 x + 5 y = 1 8 4
x - y = 3
3. y + 2 x = 3
y + 2 x = 4
I can't figure out how to break them down in the right order. Penny Nom lui répond. |
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The substitution method |
2009-02-18 |
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Nicolette pose la question : I am working on linear programming problems that I need to solve pairs of linear equations for. I am confused and am not sure how to solve these problems!
5x+3y=7 y=x-3 How can i solve this using the substitution method? Penny Nom lui répond. |
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A line parallel to a given line |
2009-02-18 |
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Lisa pose la question : I'm having a hard time understanding the concept of how to write an
equation of the line containing the given points and parallel to the given line.
Express the answer in the form of y=mx+b.
(7,9); 2x+5y=4. i would appreciate it alot if someone can show ne how
to do this. Thank you, Lisa Penny Nom lui répond. |
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Solving an equality |
2009-02-10 |
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Deborah pose la question : 2(v+10)<18 Penny Nom lui répond. |
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Linear speed |
2009-01-26 |
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Hom pose la question : A semi is driving cross country at 70mph. The tires on the semi have a 3 foot diameter. What is the linear speed in feet per minute? Robert Dawson lui répond. |
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Using y = mx + b |
2009-01-26 |
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Caroline pose la question : How do you write a symbolic representation using the y=mx+b method? Robert Dawson lui répond. |
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Solve for x |
2009-01-16 |
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maritza pose la question : 5=3(x-2)= Penny Nom lui répond. |
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0.0708 lbs per linear yard |
2009-01-16 |
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Kevin pose la question : If I know that my product is .0708lbs per linear yard how do I calculate how many Linear yards are in a lb? Penny Nom lui répond. |
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The table of values for y=3x-10 |
2009-01-09 |
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Jade pose la question : How can I know the value of x for y=3x-10 in this table of values pls. include the deatails
if x=-2 y=-16
if x=3 y=-1
but how if y=2 what is x Penny Nom lui répond. |
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A line in slope intercept form |
2008-12-08 |
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laurie pose la question : the question: Write and equation of the line that passes through the point
and has the give slope. Then rewrite the equation in slope intercept form.
(2, 5 ) m= 3 Penny Nom lui répond. |
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Solve 3x +5= 4x-10 |
2008-11-22 |
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Nikko pose la question : HELP please how do I solve these type of questions? 3x +5= 4x-10 or 4x +10= 6x-8 Penny Nom lui répond. |
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A belt drives a pulley |
2008-11-03 |
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Rebecca pose la question : A point on a belt is moving at the rate of 30 ft/sec and the belt drives a pulley at the rate of 200 rpm. What is the radius of the pulley? Penny Nom lui répond. |
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A linear system |
2008-10-22 |
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Tiffany pose la question : solve:
x + y + z = 4
2x - 3y - z = 1
4x + y - 2z = 16 Penny Nom lui répond. |
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Two equations in two unknowns |
2008-10-17 |
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Dushayne pose la question : Please help me in solving this problem:
a. 3x-4y=32
5x+2y=10
b. 2x+3y=11
4x+3y=10 Penny Nom lui répond. |
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Using the augmented matrix |
2008-10-17 |
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Karlena pose la question : I am supposed to write the augmented matrix of the system and use the matrix method to solve the system. I must show my work algebraically
x+y+2z=30
2x+3y+2z=53
x+2y+3z=47 Harley Weston lui répond. |
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Linear and Angular Velocity |
2008-10-10 |
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Matthew pose la question : The pedal and gear relationship of a bicycle is shown. The radii of the gears are r(sub1) = 5 cm and r(sub2)= 12 cm. The radius of the wheel is r(sub3) = 30 cm. How many rotations per minute of the pedal gear will produce a racing cyclist's speed of 60 km per hr.
For a diagram: http://bikepedalsgears.weebly.com/ Stephen La Rocque lui répond. |
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A linear equation with fractions |
2008-10-07 |
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Christopher pose la question : 1/6(x-18)+1/8(x+8)=x-9 Penny Nom lui répond. |
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The vertices of a triangle |
2008-09-27 |
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T. pose la question : how do you find the coordinates of the vertices of the triangle with the sides determined by the graphs of the following equations:4x+3y+1=0,4x-3y-17=0,4x-9y+13=0? Harley Weston lui répond. |
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Collinear |
2008-09-08 |
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Patrick pose la question : On page 17 of my son's 9th grade math book Geometry by Jurgensen, Brown, and Jurgensen (copyright 2004),
the authors state from the diagram that you can conclude the points A, B, and C are collinear.
In the diagram, the points A, B, and C appear to be situated on a straight line; however,
nothing in the diagram states that it is a straight line. I told him that you can't conclude they are collinear
because angle ABC could be 179.9 degrees instead of 180 degrees since nothing in the diagram states otherwise.
His teacher marked his answer incorrect on a test but I still believe that I am correct. How do conclude points are
collinear if nothing tells you that they are situated on a line? Harley Weston lui répond. |
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A word problem with three numbers |
2008-09-02 |
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Wanda pose la question : "Jabari is thinking of three numbers. The greatest number is twice as big as the least number. The middle number is three more than the least number. The sum of the three numbers is 75. Find the numbers." Victoria West lui répond. |
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Angular & Linear Speed from a Sine Graph |
2008-08-19 |
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Kim pose la question : Kim, a student:
I am given a graph with a wave. The amplitude is 5cm and the period is 4cm. I am suppose to find the angular speed. What I need to know is the formula for angular speed and how do I use these numbers to get the correct answer. Janice Cotcher lui répond. |
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A linear function |
2008-08-07 |
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Warren pose la question : What are the conditions of the numerical coefficients of the standard form Ax+By=C in Linear Function?
How will you transform y=square root of 3 x + 1 in standard form Ax+By=C? Penny Nom lui répond. |
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Two equations in two unknowns |
2008-08-01 |
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James pose la question : Question from james, a student:
3x+2y=9;24x-2y=18
My math teacher says that it is (2,-4)
Can someone please explain how to figure this out by graphing? Victoria West lui répond. |
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Simultaneous equations |
2008-07-23 |
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Franco pose la question : Solve
3 D + E - F = -10
-2 D - F = -4
-3 D - 4 E - F = -25
Franco Penny Nom lui répond. |
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A rectangular room |
2008-06-30 |
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Peter pose la question : A rectangular room has a perimeter of 42 feet and an area of 108 square feet. What is the length, in feet, of the shorter side? Penny Nom lui répond. |
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Substitution method |
2008-05-30 |
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taquicia pose la question : 2y-x=3
x=5+y Janice Cotcher lui répond. |
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x/4 = 3 1/2 |
2008-05-30 |
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Kelsey pose la question : How do you solve for "X" in the problem below?
X
--- = 3 1/2
4
--Kelsey Victoria West lui répond. |
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How old are the sisters? |
2008-05-11 |
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George pose la question : Theresa is four years older than her younger sister Joni. Twelve years ago, she was twice as old as her sister.
Find the present age of the two siblings. Penny Nom lui répond. |
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A linear model |
2008-05-09 |
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Shelby pose la question : How would you write a linear model to represent the population of a city that has a population of 547,725 and a growth rate of -25,195 per year with t represents the number of years since 1994? Penny Nom lui répond. |
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15 + 0.10n = 0.25n, solve for n |
2008-04-24 |
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monica pose la question : 15 + 0.10n = 0.25n
Solve for n. Penny Nom lui répond. |
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x/3 -5 = 3(x-2) |
2008-04-20 |
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Mrs pose la question : I am having trouble helping my son solve the following equation:
x/3 -5 = 3(x-2) Penny Nom lui répond. |
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A linear system |
2008-03-10 |
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sandhiya pose la question : one group of people purchased 10 hotdogs and 5 soft drinks at a cost of
$12.50. a second group bought 7 hotdogs and 4 soft drinks a ta cost of $9.00
find the cost of a single hot and a single soft drink.(using the row echelon form to solve) Penny Nom lui répond. |
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Simultaneous equations |
2008-02-29 |
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CONOR pose la question : I was wondering if you could help me with this problem
7x - 5y = -1
3y = 4x Penny Nom lui répond. |
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A inear system |
2008-02-03 |
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Kelly pose la question : is (-1,5) a solution of each system? y=-x+4 y=-1/5x Penny Nom lui répond. |
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Two equations in x and y |
2008-02-01 |
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leslie pose la question : 6x+8y=40 4x+5y=25 Penny Nom lui répond. |
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Linear feet to metres |
2008-01-25 |
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Jillian pose la question : i have a measurement of something in linear feet. i dont know what a linear foot is so i want to convert it to meters to have an idea.
how do i convert. Penny Nom lui répond. |
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A linear system |
2008-01-22 |
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Lisa pose la question : I am supposed to use augmented matrices to solve this system of equations. x - 3y = 5; 4x - 12y = 13. I think it is unsolvable but I want to be sure I am not just giving up. Thanks in advance for your help! Lisa. Stephen La Rocque and Brennan Yaremko lui répond. |
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How many rolls of stock do I need to buy? |
2008-01-16 |
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Dan pose la question : How many rolls of stock do I need to buy?
Given:
The rolls are 40" wide, 20" roll o.d., 4" core o.d., gauge is 0.008"
I need to cut these master rolls in 6" strips (4" of waste per master roll)
and I need 1,270,500 linear feet of this strip. Stephen La Rocque lui répond. |
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Linear systems |
2008-01-10 |
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Sandra pose la question : I have two questions. Please solve both. Thank you.
1.) In your chemistry class, you have a bottle of 5% boric acid solution and a bottle of 2% boric acid solution. You need 60 milliliters of a 3% boric acid for an experiment. How much of each solution do you need to mix them together?
2.) You plant a 14-inch hemlock tree in your backyard that grows at a rate of 4 inches per year and an 8 inch blue spruce that grows at a rate of 6 inches per year. In how many years after you plant the trees will the trees be the same height? How tall will each tree be?
Thank you. I did not understand neither problem, so I could not show any work. Please help. Stephen La Rocque and Harley Weston lui répond. |
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Donuts and bagels for the first period class |
2008-01-08 |
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Karen pose la question : Mr. Pace bought breakfast for his first period class. Ten donuts and fifteen bagels
cost a total of $15.75. Mrs. Pace bought breakfast for her class. Five donuts and twenty
bagels cost a total of $17.00. Set up and solve a system of linear equations to determine the cost
of one donut and one bagel. Penny Nom lui répond. |
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What is the speed of the plane in still air? |
2008-01-05 |
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oscar pose la question : A plane flies 400 miles with the wind and 340 miles against the wind
in the same length of time. If the speed of the wind is 24mph, what is
the speed of the plane in still air? Penny Nom lui répond. |
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Linearize a graph |
2007-12-19 |
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Justene pose la question : My daughter has a physics lab where she must linearize a graph of acc vs. mass. I have no idea how to help her. Stephen La Rocque lui répond. |
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An augmented matrix |
2007-11-29 |
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Beth pose la question : I am having troubles fiinding this augnmented matrix. I know how to do it
but everytime i do it it get a different answer and its not the right answer.
Could you help me to make sure I do it right?
Here is the problem:
4x - 3y = 5
2x +9y = 6 Harley Weston lui répond. |
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I have a piece of material 44 inches by 78 inches |
2007-11-02 |
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Marianne pose la question : I have a piece of material 44 inches by 78 inches. How many linear yards can I get from it? Penny Nom lui répond. |
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collinear points |
2007-10-26 |
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Carl pose la question : the points H,S,D,K,L, and B are collinear.
KS+SB=KB
DH+HS=DS
DH+HK=DK
point L and B are not between any other labeled points on the line.
<-------------------------------------------------------------------------> Penny Nom lui répond. |
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Domain and range |
2007-10-12 |
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Dawn pose la question : Hi, I've been out of school for 8 years and recently picked up a math correspondence course. I'm having trouble trying to figure out the range and domain of a linear function. I've read everything I can find in my text, lessons and on your site and I still can't figure out what I'm suppose to be doing. The function is y=2x+1. Please help. Penny Nom lui répond. |
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Finding equations, intersection point of two lines at right angles |
2007-09-22 |
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Yaz pose la question : Find the equation of the line joining A(-1,-9) to B(6,120). Another line passes through C(7,-5) and meets AB at rigth angle of D. Find the euation of CD and calculate the co-ordinates of D. Stephen La Rocque lui répond. |
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Two equations in two unknowns |
2007-09-22 |
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Mary pose la question : Having problems doing this problem, looking for a solution with the work. I would like to see how you got your answer, to see what I was doing wrong.
solve using the substitution method, is there "no solution" or "infinitely many solutions"
4x+y=4
2x+8y=0 Stephen La Rocque and Leeanne Boehm lui répond. |
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A nonlinear system |
2007-08-14 |
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Marsia pose la question : Explain how the solution of a nonlinear system could be just a point, or two points. Sketching these may make it easier Penny Nom lui répond. |
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Linear systems and inverses |
2007-08-06 |
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Marsia pose la question : explain how inverses are used to solve linear systems. Penny Nom lui répond. |
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A linear system |
2007-06-29 |
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Kim pose la question : solve for x,y,z
x-y+z=4
2x+2y-z=-2
x-2y+2z=7 Harley Weston lui répond. |
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The substitution method |
2007-06-23 |
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mary pose la question : solve the system by the method of substitution:
-5x+2y=-15
4x-y=9 Stephen La Rocque lui répond. |
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Factor X^6 - 64 |
2007-06-20 |
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Krystal pose la question : How do I Factor X^6 - 64 into linear factors? Penny Nom lui répond. |
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A system of linear equations |
2007-06-14 |
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Alfredo pose la question : A student club sponsored a jazz concert and charged $3 admission for students, $5 for faculty, and $8 for the general public. The total ticket sales amounted to $2542.
Three times as many students bought tickets as faculty. The general public bought twice as many tickets as did the students. Set up the equations that determine how many
tickets were sold to each group and solve. Stephen La Rocque and Penny Nom lui répond. |
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What happens when you have zero's on both sides? |
2007-06-05 |
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Lily pose la question : On the substitution method what happens when you have zero's on both
sides of the equation? Is that considered no solution or infinitely many? Stephen La Rocque and Penny Nom lui répond. |
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Linear growth |
2007-05-11 |
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Rebecca pose la question : What is the definition of linear growth? Penny Nom lui répond. |
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The substitution method |
2007-05-08 |
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A student pose la question : I need help on these two problems( substitution method)
-2x+7y=10
x-3y= -3
and
6x-8y= -12 -3x+4y=9 Penny Nom lui répond. |
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The vertices of a triangle |
2007-05-02 |
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natakie pose la question : Find the coordinate of the vertices of a triangle whose sides lie on the following three lines.
2x+5y-16=0, 4x-3y-6=0 and 3x+y+2=0 Penny Nom lui répond. |
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Two equations |
2007-04-29 |
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lavon pose la question : I'm having trouble figuring out a linear equation, can you help?
- 3x + 2y = 8
3x + 2y = 8 Penny Nom lui répond. |
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Finding out if two line equations are parallel or perpendicular |
2007-04-28 |
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Vincent pose la question : Can you determine if the two lines are parallel, perpendicular, or neither
1/2x+4y=3/5
y/1 + 10/5= 8x
I think there perpendicular but how would you solve the equations Stephen La Rocque lui répond. |
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A linear system |
2007-04-25 |
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Tee pose la question : 2x -y =5
2x +=y =5
and also
3/7x + 5/9y =27 (fractions)
I have to find the addition method to both problems Penny Nom lui répond. |
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Linear programming |
2007-04-24 |
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Sylvia pose la question : What is graphing linear programming? Penny Nom lui répond. |
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Solving Quadratic-Liner Equations algebraically |
2007-04-12 |
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Hector pose la question : Solving Quadratic-Linear Equations algebraically.
y=x^2-4x+3
y=x-1 Stephen La Rocque lui répond. |
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No solution to a linear system |
2007-04-09 |
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Ryan pose la question : When is it possible to get no solution when solving a linear system? Leeanne Boehm, Steve La Rocque, Penny Nom and Melanie Tyrer lui répond. |
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Solve for x and y |
2007-03-27 |
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anthony pose la question : solve y=4x and x+y=5 Sara Ulmer lui répond. |
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A linear system |
2007-03-23 |
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Adam pose la question : Solve the system by graphing: 4y>6x
-3x+2y<-6 Stephen La Rocque and Penny Nom lui répond. |
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Simultaneous equations with fractions |
2007-02-28 |
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Alyca pose la question : Hello Math Central, I am a grade 10 student taking Academic math. Our unit right now is method of substitution and elimination. I'm stuck on this one question that I've been doing forever. Please help =)
*For this equation I have to do method of elimination, but it's so much harder with fractions...could some one please explain to me how to do it step by step?* x y 2 -- - -- = - -- 3 6 3 x y 1 -- - -- = 1--- 12 4 2
Steve La Rocque and Ashley Mang lui répond. |
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An augmented matrix |
2007-02-13 |
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Mary pose la question : I've been trying for quite some time now to figure this out. I have to solve this by using the Gauss-Jordan Method: 3x - y = 15 2x + 3y = 10 Can anyone help me? Penny Nom and Gabriel Potter lui répond. |
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Dividing money unequally |
2007-02-06 |
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Linda pose la question : I have a total of $13,826.48. It is to be divided by 15 kids - 2 of the kids only get half of what the other 13 do - how much do the 13 get and how much does the 2 get? Thanks Haley Ess and Steve La Rocque lui répond. |
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Nickels, dimes and quarters |
2007-02-05 |
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Avinash pose la question : Mary has 48 coins made up of nickels, dimes and quarters with a total value of $5.10. She has 4 more dimes than nickels and quarters combined. How many coins of each kind does she have? Use matrix to solve the system Stephen La Rocque lui répond. |
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Patrick's new job |
2007-02-02 |
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kathy pose la question : patrick has been offered jobs by two different automobile repair shops. his income from the first shop will be $1,200 per month plus 3% of the monthly sales. the second shop will pay patrick $1,500 per month plus 2% of the monthly sales. part a let s equal the amount of monthly sales and i equal patrick's income in dollars. write a system of two equations that could be used to determine the monthly income from either shop. part b solve the equation to determine what amount of monthly sales for each shop would result in patrick earning the same monthly income, i, from both shops Penny Nom lui répond. |
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The substitution method |
2007-01-31 |
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Victoria pose la question : how do i solve this problem using the substitution method? 2x-5= -14 -7x+14y= -5 Stephen La Rocque lui répond. |
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The elimination method |
2007-01-31 |
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Addrianna pose la question : x-2y=2 3x-5y=7 Stephen La Rocque lui répond. |
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A boat travels 60 miles downstream in the same time it takes to go 36 miles upstream |
2007-01-27 |
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Liz pose la question : A boat travels 60 miles downstream in the same time it takes to go 36 miles upstream. The speed of the boat in still water is 15 mi/h greater than the speed of the current. Find the speed of the current. Stephen La Rocque lui répond. |
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The sum of the digits of a two-digit number is 13. |
2007-01-27 |
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Liz pose la question : The sum of the digits of a two-digit number is 13. If the digits are reversed, the new number is 9 more than the original number. Find the original number. Penny Nom lui répond. |
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An algebra exercise |
2007-01-24 |
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Clara pose la question : Given x + 2y = -2 and x - 2y = 18, find: a) x^2 - 4y^2 b) x^2 + 4y^2 Stephen La Rocque and Penny Nom lui répond. |
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Points of intersection |
2007-01-18 |
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Mark pose la question : Find the points of intersection of the given pair of curves. 2x - 3y = -8 and 3x - 5y = -13 Steve La Rocque and Haley Ess lui répond. |
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x + 2y < 6 |
2007-01-06 |
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Mike pose la question : I understand solving by graphing, but i am having trouble with the graphing of in equalities. i solved : x + 2y<6 Penny Nom lui répond. |
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A linear system |
2007-01-04 |
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Harold pose la question : System A (4, 2/3) 2x-3y=6 and x-3y=2
I approached this problem using the addition method.
Could i have found the answer using the graphing method? Penny Nom lui répond. |
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Linear inequalities |
2006-12-01 |
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Susan pose la question : how would I graph a linear inequality of y>3. Stephen La Rocque lui répond. |
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How high is the satellite above the earth? |
2006-11-13 |
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Naomi pose la question : If the linear speed of a satellite in synchronous orbit is 1000 mi/h, how high is the satellite above the earth? Stephen La Rocque lui répond. |
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Solving a linear equation |
2006-10-12 |
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Eriona pose la question : 6p-5=17. I have to solve the equation. Penny Nom lui répond. |
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Plotting a linear equation |
2006-10-09 |
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Jennifer pose la question :
I am having problems explaining how to do these problems to my child .
graph:2=x-y
graph the equation: 2y+x=-3
Penny Nom lui répond. |
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Linear systems |
2006-09-21 |
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Alexander pose la question : Hello, i have a math assignment due tonight at midnight and i need some help please
It is using the addition method to solve linear systems Penny lui répond. |
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Convert a standard form to a slope intercept form |
2006-09-14 |
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Maiko pose la question : I need to know step by step procedures to convert a standard form to a slope intercept form? Penny Nom lui répond. |
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I want to calibrate a glucose meter |
2006-07-27 |
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John pose la question : If I have 3 glucose control solutions having:
Low - 50 mg/dl
Normal - 100 mg/dl
High - 330 mg/dl
I want to calibrate a glucose meter but I need more than these 3 data points. How can I mix these up to get different concentrations in between 50 and 100, 100 and 330. I would like to mix up different concentrations and put them in test tubes or whatever to do some calibration work. Like 70 mg/dl, 90 mg/dl, etc. More data points should be in between say 50 and 100 since this is normal, 90 mg/dl is considered close to normal.
Stephen La Rocque lui répond. |
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How old is y = mx + b? |
2006-07-05 |
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Beckie pose la question : I am taking intermediate algebra this summer (Math 95), and have a question for you. My instructor will award extra credit points to any of us who find out how old the formula
y = mx+b is. Would you happen to know the answer? Penny Nom lui répond. |
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Square feet and linear feet |
2006-06-10 |
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Richard pose la question : Need to know how many linear ft are in 2800 sq.ft Penny Nom lui répond. |
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Three people go to a store where there is a sale |
2006-05-30 |
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Geocee pose la question : Three people go to a store where there is a sale. One person buys two shirts, one pair of pants and one sweater. The second person buys one shirt, two pairs of pants and two sweaters. The third person buys three shirts and four pairs of pants. Find the price of each item if the first person spent $155 and the second and third person spent $235 each. Stephen La Rocque lui répond. |
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Absolute Value vs. Standard Deviation ? |
2006-04-24 |
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Sonia pose la question : Why we don't just take the average of the absolute value of difference scores (use the mean deviation) to describe variability instead of calculating the standard deviation? Claude Tardif lui répond. |
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Finding the inverse of a function |
2006-04-12 |
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Sam pose la question : If g(x) = 2x+3/5 then how do I find the inverse? Walter Whiteley lui répond. |
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x-7=20 and 2x+5=17 |
2006-04-04 |
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Janette pose la question : I'm trying to help out my daughter, it has been much too long since I've been in school. The question is x-7=20 and the other question is 2x+5=17. What are the formulas? Penny Nom lui répond. |
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2x+5y=3 And -x+3y=-7 |
2006-04-03 |
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Lloyd pose la question : simplify 2x+5y=3 And -x+3y=-7
Penny Nom lui répond. |
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Angular velocity |
2006-03-28 |
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Ben pose la question : How do you (a) express angular speed in terms of linear speed and (b) express linear speed in terms of angular speed? Stephen La Rocque lui répond. |
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Linear feet on a paper roll |
2006-03-20 |
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Vishal pose la question : I WOULD WISH TO KNOW OF A STANDARD FORMULA BY WHICH I CAN CALCULATE THE LINEAR FEET OF A PAPER ROLL AS PER THE FOLLOWING DETAILS:-
THICKNESS: 150 GSM (GRAMS PER SQUARE METER)
REEL WIDTH: 85 CM
REEL DIAMETER: 140 CM
REEL INNER CORE: 10 CM
REEL WEIGHT: 946 KG's
Stephen La Rocque lui répond. |
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2x+3y=0 and 3x-y=0 |
2006-03-14 |
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Lisa pose la question : my name is lisa I am doing math for work and i have a math problem to solve and i need help with it here is the question 2x+3y=0 and 3x-y=0 this is one question can you help me please Penny Nom lui répond. |
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The graph of y = 2x + 1 |
2006-02-23 |
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Geneva pose la question : I'm having trouble with graphing equations like y=2x+1 which is my homework I'm not sure how to graph it. I'm in the 8th grade taking a 9th grade course algebra I. Penny Nom lui répond. |
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One boundary of a pond is parabolic in shape. |
2006-01-20 |
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Glenn pose la question : One boundary of a pond is parabolic in shape. The boundary passes through the points A(-20,45), B(40,40) and E(30,35). The equation of the parabola is of the form y=ax2+bx+c. Find the equation of the parabola and the coordinates of the vertex of the parabola. Any assistance you could provide would be greatly appreciated. Penny Nom lui répond. |
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Intercepts and slope |
2006-01-15 |
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Anthony pose la question : Given -1.7x + 0.8y=7.1:
(a) state the intercepts and slope for the graph
(b) Draw the graph Penny Nom lui répond. |
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y - y1 = m(x - x1) |
2006-01-08 |
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Greg pose la question : How do you change 2x + 3y = 7 into y - y1 = m(x-x1)?
Penny Nom lui répond. |
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Simultaneous Equations |
2005-12-21 |
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Matt pose la question : I have these two equations,
336 = 60a + 10b
and
432 = 84a + 6b
Am I right in saying both a and b are 4.8? Penny Nom lui répond. |
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5(x-3)/4 =x+1 |
2005-12-14 |
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Jennifer pose la question :
I have two problems i am stumped on I don't know how to help my daughter.
5(x-3)/4 =x+1
3(x+12)/5 =x +2
Penny Nom lui répond. |
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2/n +4 = 10- 4/3n |
2005-12-11 |
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Jennifer pose la question :
2/n +4 = 10- 4/3n
5(x-3/4) = x+1
Penny Nom lui répond. |
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Solve for x |
2005-12-04 |
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Lisa pose la question : 5(x-4)=3(2-3x) Penny Nom lui répond. |
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Express t as a function of d |
2005-11-30 |
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Matthew pose la question :
I have a problem on my homework I cant seem to figure out. Basically it gives me this Linear Regression Equation:
ln t=1.5 ln d-0.8954
and it wants be to transform the equation expressing t as a function of d. For some reason I keep getting it wrong. Anyone got an idea of how to do this?
Penny Nom lui répond. |
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Graphing two lines |
2005-11-20 |
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A student pose la question : About y = 5x + 24 and y = -3x - 8
1. Graph both equations on the same set of axes. When you made your graph, how did you choose the range of x and y values?
2.Find the point of intersection for the graphs.
3. Test the point of intersection you found by substituting its coordinates into the equations. Do the coordinates fit the equations exactly? Penny Nom lui répond. |
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Solving a pair of equations |
2005-11-10 |
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Steven pose la question : what is answer to
2 x + y = 1
y = -1/3 x - 4 Penny Nom lui répond. |
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What is the angle between 2 non-collinear parallel lines? |
2005-10-17 |
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Ben pose la question : What is the angle (if any) between 2 non-collinear parallel lines? Chris Fisher and Walter Whiteley lui répond. |
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2x - 5x + 6.3 = -14.4 |
2005-10-16 |
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Leslie pose la question : How do we solve 2x - 5x + 6.3 = -14.4 Penny Nom lui répond. |
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A piecewise function |
2005-09-15 |
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Duncan pose la question : A child is assigned to your care and she has a headache. The parent has authorized the administration of Children's Tylenol. Read a box of Children's Tylenol (or any other similar drug) and find the directions for administration. Note the child's weight and the corresponding dosage. (Be sure the drug you choose has a minimum of 4 weight intervals.)
Penny Nom lui répond. |
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Graphing a linear inequality |
2005-08-26 |
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Gina pose la question : When graphing a linear inequality, how do you know if the inequality represents the area above the line? Penny Nom lui répond. |
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Labour efficiency |
2005-08-23 |
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Rob pose la question :
The problem, on the surface, seems very simple and yet has created some controversy among a group of accountants. The problem itself has to do with labour efficiency rates and only involves two variables; standard working hours, and actual working hours. The difficulty lies in deriving an efficiency % from these two numbers.
Standard working hours or the targeted number of labour hours required to produce one widget, which I will represent as "s". Actual working hour or the actual number of labour hours require to produce one widget, which I will represent as "a". Labour efficiency I will represent with "E". The prevailing calculation with which I have a problem with is this:
s/a=E or if s=3000, and a=4000 then 3000/4000=75%
What bothers me about the calculation is that the standard hours get represented as a percentage of the actual hours and in my opinion changes the focus of the calculation from standard or target, where it should be, to the actual hours. I cannot define why, but this just seems inherently wrong to me.
The calculation that I use:
(1+((s-a)/s))=E or if s=3000, and a=4000 then (1+((3000-4000)/3000))=66.67%
My calculation is like a %change from standard calculation. However, there is something that also concerns me about my calculation.
If you substitute 100 for a and 50 for s, then you come to a quandary, because if you plug those numbers into the second equation the result is of course zero % efficient which doesn't sit right with me either. If you plug them into the first calculation you get 50% efficiency which doesn't really seem to work either, because you require 100% more hours to do the same work in this case. ???
Is the first calculation correct? Am I missing something altogether? Are both calculations off base? Harley Weston lui répond. |
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The substitution method |
2005-06-28 |
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Addie pose la question : how do i know where to began the substitution method? how do i solve
y = x + 1
2x - y = 1 Penny Nom lui répond. |
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An ODE |
2004-11-10 |
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David pose la question : I have a question that i really cant do, it is as follows:
The ODE dy/dx + 0.5y = 0.5e^(-1.5x) ; y(5) = 2
Solve the ODE subject to the given condition using exact methods and evaluate the solution y for x = 5 x=5.2 x=5.4 x=5.6 x=5.8 x=6 Harley Weston lui répond. |
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Pizza for Jack? |
2004-09-16 |
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Grace pose la question : Jack is playing pool with Jim for $1 a game. He has only $2 and decides to play until he goes broke or has $5, at which point he will quit and go out for a pizza with Jim(Dutch treat). Jack knows from past experience that he beats Jim 60% of the time. What is the probability that Jack will get to eat pizza? Hints: Let A be the 6x6 matrix defined by A=[aij], where aij is the probability that Jack will have $(i-1)after one game is he starts with $(j-1). For example, a23 - .40 since there is a 40% probability that Jack will end up with $1 after a game is he starts the game with $2 (If Jack wins 605 of the time, he must lose 40% of the time). Also, for example, a52 = 0 since there is no way jack can have $4 after one game if he had $1 at the beginning of the game. Since Jack will stop if he goes broke or accumulates $5, a11 and a66 are both 1.
Let x0 = [0 0 1 0 0 0 ] transposed, which we interpret as saying that initially Jack has $2 with a probability 1. Then Ax0 will represent the porbability of each amount of money, $0-$5, after one game. What is the probability that Jack will be able to eat pizza by computing Akx0 for large k and finding a limiting value. Penny Nom lui répond. |
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Solving an equation |
2004-06-14 |
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Anthony pose la question : I was hoping that you could help me with this problem. I believe that this is a high school level problem but as an adult who has forgotten the "rules", I am stuck.
the equation is this: x=t2/(t1-t2)
we know that x=5.73
t1=303
we must solve for t2 Penny Nom lui répond. |
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Solving an equation |
2004-01-03 |
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A student pose la question : the question is to solve and check equations and the question is
2n + 3n + 7 = -41 Penny Nom lui répond. |
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Making a windmill |
2004-01-02 |
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Matthew pose la question : I am a farmer in Ontario. It has been almost 20 years since high school. I am toying with making a windmill. The output chart for the the old generator I have is shown below. Before I tear it appart I would like to develop a formula from the chart that can predict the output at various speeds. Penny Nom lui répond. |
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Mr.Carter is very cautious |
2003-11-26 |
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Bob pose la question : Mr.Carter is very cautious. He decides to invest in only three stocks: one low stock, one high stock, one medium stock. Given that the expected annual yields are 6% for low stock, 7% for medium stock, and 8% for high stock, he wants his investment in medium stock to be half of his total investment in low and high stock. How much should I invest in each type fo stocks to expect a total annual return fo $650 form my investments? Harley Weston lui répond. |
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The substitution method |
2003-04-14 |
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Patty pose la question :
I need help with the following: 5x - 4y = 13 2y + 3x = -1 Penny Nom lui répond. |
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Two investments |
2003-02-07 |
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A student pose la question : you have $7200 in principal and invest different sums @ 10% and 14%. You receive 920 at end of term. (one year)What amounts are invested at what rate? Penny Nom lui répond. |
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Two equations in two unknowns |
2003-02-06 |
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Patrick pose la question : What are all ordered pairs of real numbers (x, y) for which: yx2 - 7x + 12 = 1 and x + y = 6? Penny Nom lui répond. |
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Collinear Points |
2003-01-13 |
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Gary pose la question :
Which of the 4 points are collinear when you construct the following concurrent lines or rays of a triangle? - P(1), the point where the angle bisectors intersect.
- P(2), the point where the altitudes (or extensions) intersect (inside or outside of the triangle).
- P(3), the point where the medians intersect.
- P(4), the point where the perpendicular bisectors (or extensions) of the three sides of a triangle intersect.
This is for my 9-12 high school class in geometry. My name is Gary Thanks for your help. Gary
Harley Weston and Chris Fisher lui répond. |
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The intersection of conics |
2002-12-19 |
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Glenda pose la question : We are studying systems of equations where two conic sections are the two equations that we are solving simultaneously. We were studying the number of solutions that are possible if you have an ellipse and a parabola. We all agree that there can be none, one, two, three or four solutions. The question that the students had for me was whether or not a portion of an ellipse and a parabola can overlap and thereby allow an infinite number of solutions. What should I tell them? Chris Fisher and Harley Weston lui répond. |
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x + y=80 and x + z=100 |
2002-11-28 |
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PJ pose la question : x + y=80 x + z=100 can you solve for x, y or z? Penny Nom lui répond. |
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A two stage rocket |
2002-11-26 |
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Hoda pose la question : a two stage rocket accelerates in free space by ejecting fuel at a constant relative speed , v(ex). the full fuel load makes up 80% of the initial mass of the entire two stage rocket . the rocket accelerates from rest until at the end of the first stage when 75% of its fuel has been burnt. find an expression for the speed of the rocket at the end of the first stage in terms of v(ex). Claude Tardif lui répond. |
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Performance reviews |
2002-11-21 |
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Lara pose la question : Perhaps you can help. He's doing performance reviews at work. The average performance review is 3.92 on a 5.0 scale. This person would receive a 3.5% raise for next year. The highest performance review is 4.9 and this person would recieve a 6.0% raise for next year. How do I solve for the other performance review numbers. Penny Nom lui répond. |
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The substitution method |
2002-11-15 |
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A student pose la question : Solve by using the substitution method. x = 3y - 1 x + 2y = 9 Penny Nom lui répond. |
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Determining a parabola |
2002-11-06 |
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Shelley pose la question : let (0,3) and (1,9)and (-1,1) be given points in a parablola. Determine a b and c Penny Nom lui répond. |
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A linear function |
2002-09-09 |
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Chad pose la question : If y = 9x - 13 does it represent a linear function? And if it does what is its slope and is it a direct variation? Peny Nom lui répond. |
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Two equations |
2002-07-26 |
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Derek pose la question : 1. 3x + 2y = 4 2. -7x + 2y = 24 finding x and y. Penny Nom lui répond. |
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Linear programming |
2002-05-27 |
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Jes pose la question : A machine shop makes two parts, I and II, each requiring the use of three machines, A, B, C. Each Part I requires 4 minutes on Machine A, four minutes on Machine B and five minutes on machine C. Each Part II requires five minutes on Machine A, one minutes on Machine B and six minutes on Machine C. The shop makes a profit of $8 on each Part I and $5 on each Part II. However, the number of units of Part II produced must not be less than half the number of Part I. Also each day the shop has only 120 minutes of machine A, 72 minutes of Machine B, and 180 minutes of Machine C available for the production of the two parts. What should be the daily production of each part to maximize the shop's profit? Claude Tardif lui répond. |
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25m = 100 |
2002-04-22 |
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Megan pose la question : If 25m = 100, Then m equals what number? Penny Nom lui répond. |
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An augmented matrix |
2002-04-20 |
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A student pose la question : Hi my math teacher asked us to solve an augmented matrix. I am in twelfth grade and need help. The book we are working on is college algebra. Here it is a+2b+c=0 2a+5b+4c=-1 a-b-9c=-5 Penny Nom lui répond. |
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3/4n-6=12 |
2002-04-07 |
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Diane pose la question : I am in 6th grade advanced math and I just started Algebra. My teacher tries to explain it to me but I just can't get it. I am having difficulty understanding it. Please HELP!!! I will type a problem, if you could answer it and show your work so i can understand it that would be great. Please explain in simple terms. here is a couple problems I am having trouble with, PROBLEM #1 3/4n-6=12 Penny Nom lui répond. |
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Pairs of equations |
2002-04-04 |
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A student pose la question :
high school level student is asking
y=4x x=-4y
x+y=5 3x+2y=20
y=x-1 3x-y=4
x+y=3 2x-3y=-9
x+5y=4
3x+15y=-1
. . .
Penny Nom lui répond. |
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If the matrix A is inverible and AB =AC, then B = C |
2002-03-27 |
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Vikki pose la question : i hope you can help i am soooo stuck here goes: a)
A= 0 1 B= 1 1 c= 2 5 0 2 3 4 3 4
A,B and c are matrices Evaluate AB and Ac (which I can do) then
b) I need to prove that if the matrix A is inverible and AB =AC, then B = C. Why does this not contradict what happened in part a)? Leeanne Boehm lui répond. |
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The substitution method |
2002-02-24 |
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Joe pose la question : whats the answer to this question? 3x+y=11 x+2y=-3 its substitution method i am having alot of trouble figuring it out. send the answer as soon as possible. thank you Penny Nom lui répond. |
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Linear regression |
2002-01-16 |
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Murray pose la question : If you have a set of coordinates (x[1],y[1]),(x[2],y[2]),...,(x[n],y[n]),find the value of m and b for which SIGMA[from 1 to m=n]AbsoluteValue(y[m]-m*x[m]-b) is at its absolute minimum. Harley Weston lui répond. |
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Algebra review questions |
2002-01-14 |
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A student pose la question :
- A wildebeast was observed racing a distance of 86.4m in 4.8 seconds. Find the speed of the wildebeast in m/s.
- 8x - 7 - 5x = 23
- 7 z - 3 (z + 2) = 26
Penny Nom lui répond. |
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Simultaneous equations |
2001-12-17 |
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Matthew pose la question : 4x + y = 4 2x - 3y = 5 what is x and y Penny Nom lui répond. |
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y = zx - x - c |
2001-12-11 |
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Andrew pose la question : Could you please help me work out the value of x where: y = zx - x - c Penny Nom lui répond. |
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Two equations in two unknowns |
2001-12-04 |
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Courtney pose la question : y = 3x + 2 y = 4x - 5
solve for x Penny Nom lui répond. |
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Slope intercept form |
2001-11-27 |
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A student pose la question : what is slope intercept form? Penny Nom lui répond. |
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Matrix |
2001-11-21 |
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Hoda pose la question : I have a question about matrix multiplication; well, actually, matrix division. I am assuming that matrices are divided the same as they are multiplied; that is, row by column. But what happens if you have to divide by zero? How does this affect the resulting matrix? Patrick Maidorn and Penny Nom lui répond. |
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3x-1/2(x-4)+5= -3 |
2001-11-13 |
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Tausa pose la question : 3x-1/2(x-4)+5= -3 Penny Nom lui répond. |
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A linear inequality |
2001-09-17 |
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Eric pose la question : How can I solve |x + y| + |x - y|< =6? Penny Nom lui répond. |
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Linear regression |
2001-08-01 |
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A student and a mother pose la question : My mom is taking a correspondence course in Simple Linear Regression and Correlation Analysis and we've been arguing about the relationship between the correlation -rxy and standard estimate of error-Sy.x. I took statistics last year in high school and I remember something about the Sy.x being proportionate to the r. Are they inversely related, directly related, not related, or can only range from 0 to 1.00? Her book doesn't say very much and I believe they are inversely related. She says they're directly related. Chris Fisher and Penny Nom lui répond. |
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The best linear model |
2001-07-29 |
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Rebeca pose la question : I am a student (senior) summer hire working for Dept of the Army Resource Management. I've been assisting the Analyst in developing a model to predict training costs. The technique we used was simple linear regression. Now I've been asked for my opinion in choosing the best model I feel is better. I've chosen #1. Garrison Training but I want a second opinion before I give my choice. I've taken basic statistics last year in high school and will probably be taking more this year. Could you look over the information and give me a reason my choice would not be best? The dep variable-y, is Training costs in dolars per day. Model | Ind Variable- X | a | b | r | sy.x | 1. | Garrison Training | 126.31 | 0.982 | 0.9055 | 117.2 | 2. | Local Training | 212.16 | 1.37 | 0.7937 | 142.7 | 3. | Man Rig Area | 116.38 | 2.47 | 0.6481 | 175.6 | 4. | Major Training | 346.12 | 4.67 | 0.7280 | 167.2 | Andrei Volodin lui répond. |
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Matrix reconstruction |
2001-07-19 |
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Guy pose la question : Is there a way to get the sums of rows, columns and diagonals of an n x n matrix to reconstruct the original matrix? Walter Whiteley and Patrick Maidorn lui répond. |
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Common solution |
2001-06-02 |
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Samantha pose la question :
- Solve for common solution: x+y=6 2x-3y=2
- Solve for y in terms of x: 3x-y=4
Penny Nom lui répond. |
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Solving some equations |
2001-04-16 |
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Justin pose la question : Solve the following equations for x - x+7=10
x=
- x-7=10
x=
- 3x=7
x=
- x/3=10
x=
- .
- .
- .
- .
Penny Nom lui répond. |
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Where do the lines y=2x-4 and y=x-1 intesect? |
2001-04-06 |
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Bryce pose la question : solve the following problem by setting them equal to each other. Solve for x and y. Where do the lines y=2x-4 and y=x-1 intesect? Penny Nom lui répond. |
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Matrices |
2001-03-26 |
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Peg pose la question : What are some applications of matrices, basic trigonometry, and linear systems in the real world? I'm writing and Algebra report about where these topics are used outside of the classroom. Judi McDonald and Walter Whiteley lui répond. |
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Systems of equations |
2001-03-16 |
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joy pose la question : How do u solve problems using systems of equations? ~ finding x and y~ ex:
26 = 3x - 2y 42 = 4x + y Penny Nom lui répond. |
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The substitution method |
2001-03-05 |
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A student pose la question : Solve each system of equations by the substitution method. Show your work. - y = 8
7x = 1 - y
- y = x - 1
4x - y = 19 Penny Nom lui répond. |
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Solving Equations |
2001-02-23 |
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Stephanie pose la question : Do you know who came up with solving equations? Do you have any web-sites that can give me good information on solving equations? Do you know any history on solving equations? Do you know what solving equations is used for? And finally............Sorry about all of the questions :) Has the form of solving equations changed from the time it came out to now? Juci McDonald lui répond. |
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Linear equations |
2001-02-13 |
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Jamie pose la question : I have a question how do you do linear equation? Penny Nom lui répond. |
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Vitamins A and B |
2001-01-14 |
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Sara pose la question : A diet is to include at least 140 mg of Vitamin A and at least 145 mg of vitamin B. these requirements are to be obtained from two types of food. type X contains 10 mg of vitamin A and 20 mg of vitamin B per pound. Type Y contains 30 mg of vitamin A and 15 mg of vitamin B per pound. if type X food costs $12 and Type Y $8 per pound, how many pounds of each type of food should be purchased to satisfy the requirements at the minimum cost? Claude Tardif and Harley Weston lui répond. |
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Blood flow and age |
2001-01-11 |
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Gayle pose la question : I don't understand the second part of this problem Here is the first part that was correct. A 35yr old has 100% blood flow. A 65yr old has 64% blood flow. Find the rate of change per yr in the percent of blood flow. (This part is correct) m=(64-100)/(35-65)= -36/30= -1.2 per year of blood flow. Now, here is the second part I DON'T UNDERSTAND! .Let b represent the percent of blood flow and a represent a person's age. Write an equation that you could use to predict the percent of blood flow for a person of any age over 35. Penny Nom lui répond. |
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Networks of satellites and linear spaces |
2000-12-08 |
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David pose la question : Let us suppose some companies have collaborated to place several satellites in orbit. Let us call the set of all satellites that a given company helped place in orbit a network. Finally let us assume the following 4 rules. - There are at least two distinct satellites.
- For each pair of satellites there is exactly one network containing them.
- Each network contains at least two distinct satellites.
- For each network, there is a satellite not in it.
What is the least number of satellites. what is the least number of networks? Penny Nom lui répond. |
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A piecewise linear equation |
2000-11-24 |
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Jacky pose la question : There is a light bulb and it is given that the light bulb cost $0.75 and the cost of operating it is $0.0081 per hour. From the information give, I came up with the linear equation: Let c be total cost and Let h be hours used. Therefore: c = 0.0081h + 0.75 represents the total cost of the light bulb and the electricity. However, the second part of the question added the fact that the light bulb will only last for 800 hours. If the light bulb is replaced as soon as it burns out exactly after every 800 hours, how can I write an equation that represents that? Is it possible? What would it look like on the graph. Harley Weston lui répond. |
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Solving an equation |
2000-11-14 |
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Heather pose la question : 4x-3 = 3x+4 these kinds of problems i dont get but everything else in my math class i have got. i just dont understand it. Penny Nom lui répond. |
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Connecting to a water line |
2000-10-20 |
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Vanja pose la question : My question is...A house is to be connected to a new water main that runs along the line y=2/3x-1. The connection point at the house has coordinates (2,9), where the units represent metres. What lenght of plastic pipe is needed to connect to the water main at the closest point? Penny Nom lui répond. |
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Pillows and Cushions |
2000-09-27 |
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Fiona pose la question :
The following problem was given to grade eleven algebra students as a homework assignment. To manufacture cushions and pillows, a firm uses two machines A and B. The time required on each machine is shown. Machine A is available for one full shift of 9.6 hours. Machine B is available for parts of two shifts for a total of 10.5 hours each day. Harley Weston lui répond. |
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Buying art supplies |
2000-09-18 |
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Travis pose la question : An art teacher buys exactly 100 items at this sale, and the total cost before tax is $100. She buys at least one of each item. How many of each item does she buy? Markers $0.50 Sketch Pads $3.00 Paint Sets $10.00 Denis Hanson lui répond. |
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Two linear equations |
2000-09-14 |
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David Dean pose la question : 2a + 1b = 3.39 3a + 3b = 6.59 What formula do I use to find what a = ? Harley Weston lui répond. |
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How many planes contain a line and a point? |
2000-08-30 |
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Harold pose la question : How many planes contain each line and point? Harley Weston lui répond. |
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Slope |
2000-08-19 |
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John K. DePonte pose la question : My question is to why the variable "m" was chosen to represent the slope of a linear equation. I always told my class to think of "m" for "m"ountain slope. But what is the real reason for this? Penny Nom lui répond. |
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Two linear systems |
2000-08-01 |
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A student pose la question : please help me with this homework question. 5/x + 6/y= 19/6 3/x + 4/y =2 hint: let a = 1/x and b = 1/y substitute these expressions into the system to find a and b. Then find x and y. This is a question I answered wrong on a test: solve the given system for x, y, and z. Express your solutions in terms of a, b, and c. Penny Nom lui répond. |
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The equation of a parabola |
2000-05-22 |
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Ian Forsyth pose la question : Given the points A(0,0) B(60,10) C(24,d) find the equation of the parabola. leave the equation in terms of x, y and d if the general form of a quadratic is y = ax2 + bx + c. Penny Nom lui répond. |
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Graphing a linear function |
2000-05-17 |
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Chelsea pose la question : I need help with grahing linear functions.If you could e-mail me back the basics and how tos I would be much appriciative. Penny Nom lui répond. |
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A matrix equation |
2000-05-14 |
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A student pose la question : Right now, we are dealing with matrices and we are supposed to solve the following problem on our graphing-calculators: 2a+3b-4c+d=20 a-2b+3c-5d=-14 3a+4b-2c+3d=19 5a-b+6c+4d=-5 Penny Nom lui répond. |
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Taxis in Chicago |
2000-03-27 |
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A high school studenthigh school student pose la question : Suppose that taxis pick up and deliver passengers in Chicago, which is divided into three zones. Records kept by the drivers show that of the passengers picked up in Zone 1, 50% are taken to a destination in Zone 1, 40% to Zone 2, and 10% to Zone 3. OF the passengers picked up in Zone 2, 40% go to Zone 1, 30% to Zone 2, and 30% to Zone 3. Of the passengers picked up in Zone 3, 20% go to Zone 1, 60% to Zone 2 and 20% to Zone 3. Suppose that at the beginning of the day, 600 of the taxis are in Zone 1, 100 in Zone 2, and 300 in Zone 3. What is the distribution of taxis in the various zones after all have had two riders? Harley Weston lui répond. |
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A system of equations in five unknowns |
2000-03-20 |
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Will pose la question : I have been having some problem with the following question for some time. I would appreciate any help on solving the problem or a solution. Q: Assume that a system of equations in the unknowns x1, x2, x3, x4 and x5 when converted to row echelon form gives . . . Penny Nom lui répond. |
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Systems of linear equations |
2000-03-10 |
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Ann Marie Devereux pose la question : hi there!!, I guess I have a problem!!! 3x+4y=10 (over) 4x+y=9 2x=5y+3 (over) x=3y+1 Penny Nom lui répond. |
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Midpoints and endpoints |
2000-02-15 |
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Jessica Sipes pose la question : I need to know how to find and endpoint using the midpoint and the other endpoint. Penny Nom lui répond. |
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Ax + By = C |
2000-01-18 |
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Fatiha Khanboubi pose la question : I was wondering if you could please explain to me how I would write the equation of line through the given points [(4,1), (6,3)] in Ax+By=C form. Harley Weston lui répond. |
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Parallel lines |
2000-01-12 |
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Lori pose la question : Find an equation of the line parallel to the given line containing the given point. x + y = 2; (1,2) We know parallel line have the same slope and we know the answer y = -x + 3. Penny Nom lui répond. |
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Systems of equations |
1999-12-06 |
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Roger Hornbaker pose la question : I am having problem figuring out x and y solutions. - 5x + y = 4
3x - y = 4 - 3x + 2y = 6
- 3x + y = 0 Penny Nom lui répond. |
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The elimination method |
1999-12-02 |
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Jennifer pose la question : Could I get an answer to this one: 2x+5y=36 3x+2y=32 I have to use the Elimination method, as I already know how to do Substitution. How do I begin and show my work? I'm attempting to eliminate the values for y. Penny Nom lui répond. |
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Linear models |
1999-11-09 |
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Helen Moreno pose la question : What is a linear model? Harley Weston lui répond. |
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Why is slope designated m? |
1999-08-18 |
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Peter Komlos pose la question : Why is the slope of a line is designated by the letter "m"? Penny Nom lui répond. |
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Graphing a linear equation |
1999-05-27 |
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Dylan Bradley pose la question : Im in Grade ten and am doing linear equations, I cann't figure out how to make a chart for questions like y = -2x + 3 Penny Nom lui répond. |
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Parallel and perpendicular lines |
1999-04-23 |
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Crystal Pilling pose la question : My name is Crystal Pilling and I am in 9th grade algebra. We are currently studying parallel and perpendicular lines. I am having trouble with this problem: 3/4x - 5y= 16, (5,-6) I have to find a line that is perpindicular to this line on a graph. HELP ME PLEASE!!!!! Penny Nom lui répond. |
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Shopping at Wegman's |
1999-04-22 |
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Stan pose la question : Joanne, Steve, Pat, Alice, Joan, and Bill go to Wegman's at the same time. Joanne buys 2 gal of milk, 1 dozen oranges, 8 apples, and 2 lb. of ground beef, paying a total of $13.24. Steve buys 3 qts. of milk, 5 lbs. of ground beef, 10 lb. of potatoes, and 2 bags of mixed vegetables, paying a total of $16.95. Pat buys 3 gal. of milk, 2 dozen oranges, 1 dozen apples, 5 lb. of potatoes, and 5 bags of mixed vegetables, paying a total of $25.09. .... Find the cost of: 1 qt. of milk, one orange, one apple one lb. of ground beef, one lb. of potatoes, and one bag of mixed vegetables. Penny Nom lui répond. |
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Linear programming and optimization |
1999-04-09 |
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Shams pose la question : What is Linear programming and optimization? Jack LeSage and Penny Nom lui répond. |
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Fitting a Curve |
1999-01-19 |
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Kirk pose la question : Hello my name is Kirk from Scarborough, Ontario. I have been out of a formal education system for thirty years. I program microcontrollers in my spare time. I have built a temperature sensing device ready to go but, thermistors are very non-linear. I do know that there is a way to calculate the input condition of the thermistor and display the correct temperature in degrees C. I am sending a file to show my progression so far. Harley Weston lui répond. |
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Linear Equations |
1999-01-16 |
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Casie Tomney pose la question : My dad and I have been trying to figure, how to solve for x on any of these problems my teacher gives us. The problem is: 2h/3 + 1/2 = 5h/6 - 3/4 Thanks!!!!!!!! Jack LeSage lui répond. |
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Intersection of Planes |
1998-12-03 |
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Lindsay Fear pose la question : My name is Lindsay Fear. I am an OAC student (which is the Ontario equivalent to Grade 12 in most other states and provinces). I am in an Algebra and Geometry course and am currently studying a unit on equations of planes. Our teacher has given us this question that my friend and I have attempted several times, but we are still unable to solve it. My teacher has also suggested using the internet as a resource. The question is: Prove that a necessary condition that the three planes -x + ay + bz = 0 ax - y + cz = 0 bx + cy - z = 0 have a line in common is that a^2 + b^2 + c^2 + 2abc = 1 Walter Whiteley lui répond. |
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Algebra |
1998-11-25 |
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Casey pose la question : yeah my son brought home a math worksheet and he was wondering and me too if u could help him and me out . he has problems like this 4n+9=7n+2= ??? and he has to show work so if u could help us out that would be great Jack LeSage lui répond. |
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Linear systems of equations |
1998-11-16 |
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Crystal Girvan pose la question : My name is Crystal Girvan.Im in grade 11. I have a question.We are solving linear systems of equations: comparison method. My questions is. it says a)use the method of comparison to solve this system a=b-1, 3a+ b=3 b) verify your solutin in a I dont understand it. please help Jack LeSage lui répond. |
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A Linear System |
1998-10-08 |
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Jason Bussey pose la question : The linear systems with the following pattern all have the same solution. Is their some kind of reasoning as to why this is so? 2x+3y=4 3x+4y=5 4x+5y=6 5x+6y=7 The solution is always x=-1, y=2 Thank you Jason Penny Nom lui répond. |
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Operations Research |
1998-10-08 |
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Lisa Barrett pose la question : What is the history of operations research and the study of linear programming? Judi McDonald lui répond. |
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Seed Problem |
1998-03-26 |
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Jody A. Johnson pose la question : Seed Problem: The height of an amazing plant grown from a seed varies linearly with the time it has been in the ground. After six days it is 6cm tall and after 60 days it is 15.8m (1580 cm) tall. - Write the particular equation giving the height as a function of time.
- Find the intercepts and explain them.
- What would be the height in one year?
- How long would it take for the plant to grow to a height of 1km?
I'm having a problem with this equation. Could you please help. Thank you. Penny Nom lui répond. |
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Y-intercept |
1998-02-27 |
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Don Trumpet pose la question : What is the Y-intercept for the problem:Y = -2(x+2) + 9 Harley Weston lui répond. |
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Intersecting Lines. |
1998-02-10 |
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Erik Heppler pose la question : My typewriter frequently makes mistakes. Suppose I gave you the following system of equations to solve: 35.26X + 14.95Y = 28.35 187.3X + 79.43Y = 83.29 When I looked back, I realized that I meant to use 14.96 as the "Y" coefficient in the first equation instead of 14.95. Solving the system using 14.95 and then solving another system using 14.96 with all other values the same both times results in the intersection points (1776, -4186) and (-770, 1816) respectively. How can that be? Penny nom lui répond. |
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How many intersections? |
1997-10-08 |
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James pose la question : (a) A collection of eight points, no three collinear. If lines are drawn between each pair of these points, how many points of intersection would there be? (b) what would your answer have been in part (a) if there had been n points to start with? Chris Fisher lui répond. |
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