So negative change in anthropy vaporization over r, our common term, times one over t, final minus one over T initial. Notice that here this was a positive. But since we're taking a negative out, this becomes a negative. And to check that, we multiply this out and we should get this form. And, in fact, we do. Now, our final step before we plug in chug is simply to rewrite this so that we have this thing on one side and everything else, all the knowns on the other side.