The marketing research department of a large manufacturing company has determined that the demand equations for two major items it produces are given by p = 2,000 - 5x + 8y and q = 4,000 + 9x - 7y where p is the price of item A, q is the price of item B, x is the monthly demand for item A, and y is the monthly demand for item B. Find the total monthly revenue from items A and B when x = 15 and y = 5.