Let
Eq1 : x - 2y = 12
Eq2 : 4x + 2y = 16
For substitution, we need to rearrange on of the equations so that we can substitute it in the other. Let's pick eq2 and rewrite it as 2y = 16 - 4x. We see that eq1 also has 2y in it, so we can plug this new version of eq2 in there.
3x - (16-4x) = 12
Now solve for x.
7x=28, so x=4
Plug that into either equation to solve for y. You get y=0.
So your answer is x=4, y=0
