You can imagine this, if this was a minus b, it would be a squared minus 2ab plus b squared. That's all I did. Now I'll just have to do that for each of the terms. Each term is only different by the x and the y coordinates right over here. The next term, and I'll write it, I'll go down so that we can combine like terms. This term over here squared is going to be y2 squared minus 2 times y2 times mx2 plus b plus mx2 plus b squared. Same exact thing up here, except now it was with x2 and y2 as opposed to x1 and y1.