Country Workshop manufactures both finished and unfinished furniture for the home. The estimated quantities demanded each week of its rolltop desks in the finished and unfinished versions are x and y units when the corresponding unit prices, in dollars, are described, respectively, in the following equations.

Question

Country Workshop manufactures both finished and unfinished furniture for the home. The estimated quantities demanded each week of its rolltop desks in the finished and unfinished versions are x and y units when the corresponding unit prices, in dollars, are described, respectively, in the following equations. 
p = 310-1x-1/2y

q = 730-1/2x-1/7y 
(a) What is the weekly total revenue function R(x,y)?

NOTE; Someone else gave me this answer but it still says it is wrong. Thanks
310x - 1x^2 - 1/2xy + 750y -1/2xy -1/7y^2 -1x^2 -1/7y^2 + 310x -xy + 750y

Steve · Answer

Even if the above formula is correct, it would surely not be the correct answer, since like terms have not been combined, and the order of powers is unconventional. Also, there is no constant term, even though both P and Q contain a constant term, so there is no way it could be correct.

revenue = price*quantity, so
R(x,y) = P(x,y)*Q(x,y)

1/2 x^2 + 11/28 xy + 1/14 y^2 - 885x - 2865/7 y + 226300

I leave it to you to verify it.