Question

2x - 12 = 3y
5x + 4y = 7
Help me with Gaussian substitution please! Work me through it. I want to understand.

Answer 1

@precal

Answer 2

@SolomonZelman @Zale101 @zepdrix

Answer 3

Hey c:
So we're doing the substitution method, not the elimination method?

Answer 4

My teacher said it's Gaussian subst. where you have to multiply each side by a number then cancel out a pair of numbers.

Answer 5

Oh ok, we call that Gaussian Elimination, then we follow it up with back substitution.
If your teacher is calling it that though, no big deal.

Answer 6

Nope my mistake, I wrote it wrong in my notes haha

Answer 7

Oh hehe.
\[\Large\rm 2x - 12 = 3y\]\[\Large\rm 5x + 4y = 7\]We need all of our x's and y's on the same side.
In equation #1, let's subtract 3y from each side, and add 12 to each side.

Answer 8

\[\Large\rm 2x - 3y = 12\]\[\Large\rm 5x + 4y = 7\]Understand that first step ok? :o

Answer 9

Yes! That's the part I couldn't understand was moving the variables around.

Answer 10

I think I can work it myself. I'll try.

Answer 11

Hmm ok cool :) Yah give it a shot.

Answer 12

Is the solution (3, -2) ? @zepdrix

Answer 13

Ooo yay! Nice job!

Answer 14

Thank you! I appreciate it very much!