What's another point that's on that line? Because if you have two points on the line, you know what the equation of the line is going to be. Well, the other point, if we want this to be an mx plus b form. So let's divide both sides of this equation by this term right here, by the mean of the x's. And if we do that, we get m times the mean of the x squareds divided by the mean of the x's plus b is equal to the mean of the xy's divided by the mean of the x's. And so when you write it in this form, this is the exact same equation as that. I just divided both sides by the mean of the x's.