If we divide both sides by x, we get y is equal to negative 16 over x. And so let's replace our y in this expression with negative 16 over x. So then we would get our sum of squares as a function of x is going to be equal to x squared plus y squared. Y is negative 16 over x. Negative 16 over x. And then that's what we will now square. So this is equal to x squared plus, what is this?