The joint cost, in dollars, for two products is given by C(x, y) = xy2 + 11. (Round your answers to the nearest integer.) (a) Find the marginal cost (in dollars) with respect to x if 30 units of x and 5 units of y are produced. dollars per unit of x (b) Find the marginal cost (in dollars) with respect to y if 30 units of x and 5 units of y are produced. dollars per unit of y