The definite integral going from zero to four of f of x, dx, plus the definite integral going from four to six of f of x, dx. Pause this video and see if you can figure that out. Well, once again, this first part right over here going from zero to four, so what would be is would be this area, it would be this five right over here, but then we would need to subtract this area because this area is below our x-axis and above our curve. We don't know exactly what this is, but luckily we also need to take the sum of everything I just showed, but plus this right over here. And this we're going from four to six, so it's going to be this area. Well, once again, when you look at it this way, you can see that this expression is going to be equivalent to taking the definite integral all the way from zero to six, zero to six of f of x, dx. And once again, even if you didn't see the graph, you would know that because in both cases you're getting the definite integral of f of x, dx, and our upper bound here is our lower bound here.