Suppose that x and y represent the amounts of two basic inputs for a production process and that the equation 32x y = 2545 describes all input amounts where the output of the process is 2545 units. a) Find - dx b) What is the marginal rate of substitution of x for y when x = 625 and y = 40? dy a) dx (Simplify your answer.) b) The marginal rate of substitution of x for y when x = 625 and y = 40 is (Simplify your answer.)