If you view that you have the x and y data points, everything here is a constant except for the m's and the b's. We're assuming that we have the x's and y's. So we can figure out the mean of the squared values of y, the mean of the xy product, the mean of the y's, the mean of the x squareds. We assume that those are all actual numbers. So this expression right here is going to be, it's actually going to be a surface in three dimensions. So you can imagine this right here, that is the m axis. This right here is the b axis.