And then the second expression will be, this will go away. This is when you divide it by 2n. I don't want to say negative 2n. That's when you divide it by 2n, you get this. And when you divide this by 2n, that'll go away, that will go away, and then those will go away. And you're just left with negative, the negative mean of the y's, plus m times the mean of the x's, plus b is equal to 0. So if we find the m and the b values that satisfy the system of equations, we have minimized the squared error.