And then we're going to have, so if we add the mean of the x, y's to both sides of this top equation, what do we get? We get m times the mean of the x squareds, plus b times the mean of the x's, is equal to, these are going to cancel out, is equal to the mean of the x, y's. That's that top equation. This bottom equation right here, let's add the mean of y to both sides of this equation. And I do that so that that cancels out. And then we're left with m, do that in the blue color, show you the same equation. We have m times the mean of the x's, plus b, is equal to the mean of the y's.