And on the right-hand side, we just get 0. Derivative of a constant is just equal to 0. Now we need to solve for dy dx. So we get 2x. And so if we distribute this business times the dy dx and times the negative 1, when we multiply it times the dy dx, we get, and actually I'm going to write it over here, so we get plus 3 times y minus x squared times dy dx. And then when we multiply it times the negative 1, we get negative 3 times y minus x squared. And then, of course, all of that is going to be equal to 0.