A firm produces two different goods, with demand given by the following: Pa = 500 - 8Qa

Question:

A firm produces two different goods, with demand given by the following:
Pa = 500 - 8Qa + 4Qb and Pb = 200 - 25Qb Where Pa = price of good A, Pb = price of good B, Qa = quantity of good A and Qb = quantity of good B. The marginal costs for the two goods are 30 for good A and 40 for good B.
Determine optimal prices and quantities for each good.