I need help with this

Your weekly cost (in dollars) to manufacture X televisions and y stereos is C(X, y) = 24,000 + 30X + 20y + 0.3xy. a) Compute the marginal cost of manufacturing stereos at a production level of 15 televisions and 16 stereos. HINT [See Example 2.] $ per stereo b) Compute the marginal cost of manufacturing televisions at a production level of 15 televisions and 16 stereos. HINT [See Example 2.] $ per television