We're just using exponent properties there. And then divided everything by, let's see, oh, then everything is in terms of x to 3.5, so we're going to have negative 3.5 x to 3.5, and then you use exponent properties. So actually, it looks like he did everything correctly. This is the right answer. Now, so his work is correct. He did not make any mistakes, but I do have a bone to pick, so to speak, with Tom, because he didn't have to apply the quotient rule here. He did all of this hairy calculus and algebra, but there could have been a very simple simplification he could have made up here, and this is a key thing to realize.