So this term right over here is the exact same thing as this term over here. And then finally we have a b squared in each of these. And how many of these b squares do we have? Well, we have n of these lines, right? This is the first line, second line, then a bunch, bunch, bunch, all the way to the nth line. So we have b squared added to itself n times. So this right over here is just b squared n times.