If this is equal to that, if the left hand side is equal to the right hand side, let's just subtract this value from both sides. So on the left hand side I would have the expected value of X, that's that, minus this. Minus one minus P times the expected value of X. So I'm just subtracting this from that side but let me subtract this from that side. Well I could subtract this expression from that but this is equivalent so I'm just going to subtract this from that. And so what do I get? Well let's see, I'm going to have one minus P and then if I subtract one P times one minus P from two P times one minus P, well I'm just going to be left with plus one P times one minus P. And then if I subtract this from that, I'm going to be left with one P times one minus P squared.