







Algebre 
20090304 

Jonnathan pose la question : Pour entrer sur le site d'une exposition, il en coute 41$ pour 2 enfants et 2 adultes mais 37.50$ pour 3 enfants et un adulte. Quel est le prix de la rentree pour l'enfant et quel est le prix de la rentree pour l'adulte? il faut utiliser la methode de comparaison ou de substitution Claude Tardif lui répond. 





The substitution method 
20200610 

Hardebolar pose la question : simultaneous equation by substitution method
.ab=2/3 a+b=1 2/3 p lui répond. 





Integration of dx/(x^2+1)^3 
20160107 

Ishank pose la question : Integration of dx/(x^2+1)^3 Penny Nom lui répond. 





A linear system 
20141014 

pheter pose la question : 4/x  1/y = 3 .... equation (1)
6/x  2/y = 5 .... equation (2) Penny Nom lui répond. 





Evaluate x(3x+5) if x=2 
20140403 

Destiny pose la question : I wanted to know the value of x(3x+5) if x=2 Penny Nom lui répond. 





f(x)= a+b*lnx 
20131204 

Kevin pose la question : How do I find the curve, algebraically on paper, for f(x)= a+b*lnx with data points
(6,1303) (9,1639). I can do it with LnReg on a calculator but I want to know how
to get the same results or close to the same results by working it out on paper.
When I run it through the LnReg on the calculator I get, f(x)=181.792+828.678 Ln x.
How did it achieve this solution? Penny Nom lui répond. 





Substitution type simultaneous equations 
20131103 

Kayla pose la question : I am having problems with substitution type simultaneous equations, when the variable you are substituting is a algebraic one:
y=x^23x+4 and 3x2y=1
I have rearranged 3x2y=1 to get x=(1+2y)/3 but when I substitute this x value into the other equation, I get the wrong answers!
Would appreciate any help! Thank you. Penny Nom lui répond. 





Integral 1/(25x^2)^3/2 
20120222 

John pose la question : Integral 1/(25x^2)^3/2 Harley Weston lui répond. 





Elimination and substitution 
20100918 

Lauren pose la question : Solve one using the method of substitution and the other with the method of elimination.
v
a. y=5x+4
x=2y+1
b. 4x+3y=7
6x3y=13 Penny Nom lui répond. 





y = kx 
20100326 

harold pose la question : if y =kx and y =4/15 and x=2/3, what is value of k Penny Nom lui répond. 





The integral of X^3/the square root of 1x^2 dx 
20100307 

William pose la question : The integral of X^3/the square root of 1x^2 dx. Harley Weston lui répond. 





Substitution method 
20100217 

Melodie pose la question : 7x  4y = 10
4y= x2 Tyler Wood lui répond. 





Substitution 
20100214 

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. 





An integral 
20100129 

amr pose la question : find the value of the following integral:
(1+x)power (1/2) dx Robert Dawson lui répond. 





The method of substitution 
20090917 

laura pose la question : ok! i really need help with this question plz help!!
x=  4y +5
x+2y = 7 Penny Nom lui répond. 





Substitution in a quadratic 
20090309 

Kieran pose la question : How could I work this out please
f(x)= 3xsquared  4x + 2
if f(2x) Penny Nom lui répond. 





Linear systems 
20090220 

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. 





The substitution method 
20090218 

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=x3 How can i solve this using the substitution method? Penny Nom lui répond. 





A definite integral 
20090209 

Mathata pose la question : Evaluate: integral from 0 to 1, x^2 e^x^3dx Harley Weston lui répond. 





The substitution method 
20090206 

amber pose la question : Pleasse help me with this problem
x+y=2
y2x=1 Penny Nom lui répond. 





The integral of f(x)dx and the integral of f(x4)dx 
20090102 

Katie pose la question : Calculus:
If the definite integral from 2 to 6 of f(x)dx=10 and the definite integral from 2 to 6 of f(x)dx=3, then the definite integral from 2 to 6 of f(x4)dx= ?
I don't understand how to solve definite integrals when the function has something more than just x inside the parenthesis such as f(4x). Robert Dawson lui répond. 





The substitution method 
20080726 

Enid pose la question : Solve by substitution method
3x + 7y = 25
7x + y = 63 Penny Nom lui répond. 





A rectangular room 
20080630 

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. 





Substitution into a formula 
20080602 

beth pose la question : Given q(x) = 7xsquared + 9, find q(7)
These were the choices I had for the answers to this problem
1.) 343
2.) 40
3.) 334
4.) 89
5.) 352 Penny Nom lui répond. 





Substitution method 
20080530 

taquicia pose la question : 2yx=3
x=5+y Janice Cotcher lui répond. 





Integrate 2x(x^21)^5 dx 
20080417 

joey pose la question : pls help me to integrate
2x(x^21)^5 dx using the substitution u=x^21 Harley Weston lui répond. 





The integral of dx / (4x^2  25)^3/2 
20080401 

Meghan pose la question : I have a question from the trigonometric substitution of my calculus course.
integral of dx / (4x^2  25)^3/2 Harley Weston lui répond. 





An integral 
20080124 

Meghan pose la question : Evaluate the indefinite integral of (x^3 +1)^(1/3) * x^5 * dx. Brennan Yaremko lui répond. 





Substitution method 
20071011 

Kevin pose la question : 3xx+2y=36y=11 Stephen La Rocque lui répond. 





Two equations in two unknowns 
20070922 

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. 





Solve by substitution 
20070728 

Marina pose la question : I am stuck with this substition please help.
3x+y=1
5x+2y=4 Penny Nom lui répond. 





The substitution method 
20070623 

mary pose la question : solve the system by the method of substitution:
5x+2y=15
4xy=9 Stephen La Rocque lui répond. 





The substitution method 
20070508 

A student pose la question : I need help on these two problems( substitution method)
2x+7y=10
x3y= 3
and
6x8y= 12 3x+4y=9 Penny Nom lui répond. 





Solve for x and y 
20070327 

anthony pose la question : solve y=4x and x+y=5 Sara Ulmer lui répond. 





Simultaneous equations with fractions 
20070228 

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. 





The substitution method 
20070131 

Victoria pose la question : how do i solve this problem using the substitution method? 2x5= 14 7x+14y= 5 Stephen La Rocque lui répond. 





The substitution method 
20050628 

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. 





The substitution method 
20041128 

A student pose la question : I Was working and i ran into this problem can you help me solve it using the substitution method?
3x2y=10
x+5y=27 Penny Nom lui répond. 





The method of substitution 
20040920 

Kayla pose la question : y=x1
y=2x3 Harley Weston lui répond. 





x^2/3  7 x^1/3 + 12 = 0 
20040405 

Jackie pose la question : I am having trouble solving this question for x:
1.) x^2/3  7 x^1/3 + 12 = 0 Penny Nom lui répond. 





The substitution method 
20040214 

Keisha pose la question : I need to solve this problem by using the substitution method.
3x+y=1
x=2y+5
Please help me understand the method to solve. Penny Nom lui répond. 





Systems of equations 
20031119 

Scott pose la question : I hope that u can help me....I
am a college student taking a class in Pre Calculus.....I have homework
due this Friday and it counts a BIG Percentage on my FINAL grade.....I
am getting mixed up and can not figure out a few problems.....Please help
me.....
Method Of Subsitution
Problem 1. y 8x = 5
x(squared) + y(squared) = 25
Problem 2. y = x(squared)  2x  6
Y = x(squared)  4
Penny Nom lui répond. 





5x  y 
20031011 

Candace pose la question : math problem 5xy for x=12 and y=14 do you mulitilpy 5x12 and than the answer from 14 which gives you 46? is this right Penny Nom lui répond. 





Substitution method 
20030914 

John pose la question :
Hello, my name is john and while I was finishing up my work I stumbled into these problems. a/4b=1 a+b=11 and 6ab=5 4a3b=8 Thanks a lot. I really need some help :) John Penny Nom lui répond. 





Two equations 
20030821 

Jennifer pose la question :
The following problems have me stuck and any help would be greatly appreciated seeing my text book is doing me no favours:
3^{2a+1}  283^{a} + 9=0 and 5^{2m}  5^{m}=20 Penny Nom lui répond. 





The substitution method 
20030414 

Patty pose la question :
I need help with the following: 5x  4y = 13 2y + 3x = 1 Penny Nom lui répond. 





The substitution method 
20021115 

A student pose la question : Solve by using the substitution method. x = 3y  1 x + 2y = 9 Penny Nom lui répond. 





Substitution 
20021106 

John Paul pose la question : I took a math test last week, and there was a problem which the teacher checked as incorrect. It was:
Solve: (a)RcTc=360;(b)RmTm=480;(c)Rm=2Rc; (d)Tm+Tc=15 I solved the problem and I got the following values for each variable.
For Rc=40 For Tc=9 For Rm=96 For Tm=5 I don't see nothing wrong, but the teacher checked it as wrong. Could it be a checking mistake? Claude Tardif lui répond. 





18m11+ 7 
20021106 

Sophia pose la question : what is 18m11+ 7 (m = to 12)? Penny Nom lui répond. 





Algebra 
20020908 

Heather pose la question : This question is from an 8th grade Algebra classs. I am a parent asking for help to explain to my child. Q: d=25t^{2}. Leeanne Boehm lui répond. 





x + 5 + x, if x = 4 
20020723 

Elisa pose la question : x + 5 + x, if x = 4 Leeanne Boehm lui répond. 





The substitution method 
20020224 

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. 





The substitution method 
20010305 

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. 





Some integration problems 
20000223 

Tim Valentine pose la question : I am having a great deal of difficulty with the following integrals, can you help? I think they need the use of trig substitution or integration by parts but I cannot figure out how to begin. Thanks! The integral of 1/(2+3x^{2}) dx. and The integral of x * square root of (4x+5) dx. Harley Weston lui répond. 

