Answer:
AB=8
Explanation:
First, you get figure out x. Since both sides are equal, use the equation x+3=2x-2, then subtract x from both sides, 3=x-2, and then add 2 to both sides, x=5. Then use one of the equations to get the length of the side, I used x+3=8, which is your answer.
(hope this helps :P)