We're going to divide all of them by delta x, right? And then the last term is delta x to the n. But now we're going to divide that by delta x. So the last term becomes n choose n. x to the 0 is 1, so we can ignore that. Delta x to the n divided by delta x. Well, that's delta x to the n minus 1, right? And then what are we doing now? Well, remember, we're taking the limit as delta x approaches 0.