(picture included) where did i go wrong here? (using the combination method)

I guess by "combination" you mean elimination. You multiplied the second equation by -2, so the system is

Then eliminating by adding the first equation to the second, you'd end up with

so you all you did was forget about the -1 from the first equation.

From here, you have

so if , then . So the solution would be (2, -1).

a.

step-by-step explanation:

step 1 distribute 2 to every term in the parentheses

step 2 add 10 on both sides of the equal sign