So this area right over here, we know that that could be represented as the definite integral from a to b of f of x plus g of x dx. Now the question is, how does this thing relate to d, or how does this area relate to these areas right over here? Well, the important thing to realize is this area that we have in yellow, that's going to be this area right over here. That one's pretty clear. But how does this area in green relate to this area there? And to think about that, we just have to think about what does an integral mean? Remember, what does it represent?