And right there, we have a relationship between x and y. And if we take the derivative of both sides with respect to t, we're probably doing pretty well. Now, before taking the derivative with respect to t, I could do it right over here just to simplify things a little bit. Let me just cross multiply. So let me multiply both sides of this equation by 20 and y, just so that I don't have as many things in the denominator. So on the left-hand side, it simplifies to 20x. I don't want to write over it.