Question

solve each system by substitution.
4x-2y=-14
-12x+6y=42

Answer 1

Can we at least divide everything by 2 first to make it simpler? :)

Answer 2

?

Answer 3

Well, all of the terms are divisible by 2 so it's easier to simplify the equations a bit before doing the substitution method. The equations then become:
2x-y=-7
-6x+3y=21

Answer 4

I would do that first....but you can do it however you like.

Substitution method goes like this:
1) Take one of the equations and put x or y in terms of the other variable. Taking the first equation I posted for example:
2x-y=7
so y=2x-7

2) Take this new equation and plug it into one of the equations and solve for x.

3) Once you know what x is, plug it into one of the equations and solve for y.

Answer 5

4) Check to ensure the solution is valid by plugging x and y into both equations and make sure the equations are still true.