A firm is the only supplier of two goods, X and Y, and the demand equations for these goods are 4x + px = 200 and 2y + py 152, where PX and py are the prices of X and Y and z and y are the quantities of X and Y (respectively). The firm's joint. total cost function is C(x, y) = 6x + 4xy + 4y2 + 20. FO Find an expression, in terms of r and y, for the firm's profit function. Determine the values of az and y that maximise the profit. What are the corresponding prices?