# Algebra

It does, thanks.

I'm currently working on solving algebraic equations with two variables (Example: 3x+4y=9). The computer lesson has taught me nothing but to solve the equation by trial and error -- selecting the proper ordered pair from a multiple choice list after plugging it in to see if it's correct. So, what happens when I don't have a convenient little list of ordered pairs to plug in? Is there a way to solve it from scratch like a one-variable equation?

There is a way to solve this problem from scratch.

You first find a value for either X or Y and then plug that instead of X or Y and solve for the other one.

3X + 4Y = 9

3X = 9 - 4Y

X = (9-4Y)/3

Now plug that instead of X to make it a one variable equation.

3[(9-4Y)/3) + 4Y = 9

That should result as Y=1

Than, plug 1 instead of Y to get X.

3X + 4(1)=9

that should result as X = 5/3

Than, plug the number for both X and Y.

3(5/3) + 4(1)=9

9=9

Hope it helps.

1. 👍 0
2. 👎 0
3. 👁 98

## Similar Questions

1. ### Math/ Algebra

Post your responses to the following. Answer each question in a separate paragraph: Techniques that can simplify solving equations and inequalities are to clear fractions and decimals when solving linear equations and

asked by Amanda on June 14, 2010
2. ### algebra attn Reiny

Thanks for your help with the solving of the three equations! Yes, it was a typo. I just finished solving it a long way, solving for the 1st 2 equations then the 2nd and 3rd and plugging in variables...etc. etc. Your way gave the

asked by Terri on February 24, 2009
3. ### quick question regarding equations

I know there are methods out there but what do you think is the best or easiest method(s) of solving a system of equations. Depends on the coefficients of the equation. If in one of the equations I can solve for one of the

asked by Shawn on August 14, 2007
4. ### to annonymus can you help me with math

How do i solve inequalitites with three variables. I still can't figure it outplease help. x+y=1 y-z=-3 2x+3y+z=1 the answers are 3,-2,1 how do get there by solving linear equations with three variables. 5x-2y-z=2 -y+2z=11

asked by Jasmine202005 on October 22, 2006
5. ### Math

PLEASE CHACK MY ANSWER!!! Discussion for Applications of Linear Systems When solving a system of equations, how do you determine which method to use? My answer: I determine which method to use by looking at the equations. If both

asked by Matthew on December 15, 2016
6. ### algebra

Explain the difference between solving a system of equations by the algebraic method and the graphical method. Someone also wants to know why there are different methods for solving the same problem-what would you tell him?

asked by kiMBERLY on July 12, 2010
7. ### Equations and variables

Why are variables and equations such an important part of algebraic reasoning?

asked by Sarah on March 26, 2008
8. ### math

what is.7 of 39.4????? 39.4*.7=27.58 Having trouble solving equations with two variables..both unknown

asked by Caitlyn on March 20, 2007
9. ### Algebra

Solving systems of linear equations in 3 variables... 1) 3x-2y+2z=1 2) 2x+5y-5z=7 3) 4x-3y+z=-3 I combined 1 and 3 to get -5x+4y=7 And then i combined 2 and 3 to get -13y+11z=-17. Can that be right? how would you combine those two

asked by Max on November 13, 2010
10. ### Physics

You are given vectors A = 5.0i - 6.5j and B = -2.5i + 7.0j. A third vector C lies in the xy-plane. Vector C is perpendicular to vector A and the scalar product of C with B is 15.0. Find the x and y components to vector C. Here's

asked by Vectors on August 30, 2014

More Similar Questions