All of that over delta x. Let's see if we can simplify. So first of all, we have an x to the n here, and at the very end, we subtract out an x to the n, so these two cancel out. And then if we look at every term here, every term in the numerator has a delta x, right? So we can divide the numerator and the denominator, essentially, by delta x. This is the same thing as 1 over delta x times this whole thing. So that is equal to, let me, the limit as delta x approaches 0 of, so we divide the top and the bottom by delta x, or we multiply the numerator times 1 over delta x, we get n choose 1 x to the n minus 1.