You'll want to use integration to figure this one out. The first step is to determine the x-values where the two graphs intersect. If you set them equal to each other (or look at the graph), you'll end up with
x = -2
and
x= 1
If you need further explanation of this step, feel free to ask.
From there, determine which graph is "above" the other in the interval of intersection. In this case, the top curve is
This means your bottom curve must be
From there, integrate with your bounds from smaller to larger in the order of the top function minus the bottom function. This leaves you with the following:
Depending on how you're meant to solve this, use a calculator or perform it by hand. If there's an issue there, post another reply and we'll integrate by hand.