And then we would just reverse the substitution. We already know what u is. So this is going to be equal to the antiderivative of this expression is one over the natural log of eight times e to the, instead of u, we know that u is x to the third times the natural log of two. And of course, we could put a plus c there. Now, going back to the original problem. We just need to evaluate the antiderivative of this at each of these points. So let's rewrite this.