So once again, this is just the squared error of that line with n points, between those n points and the line y equals mx plus b. So let's see if we can simplify this somehow. And to do that, what I'm going to do is I'm going to kind of try to add up a bunch of these terms here. So if I were to add up all of these terms right here, if I were to add up this column right over there, what do I get? Well it's going to be y1 squared plus y2 squared plus y all the way to yn squared. That's those terms right over there. So I'm going to have that.