A firm produces two types of toy trains each week. The weekly revenue function is given by
R(x,y)=50x +70y +0.07xy -0.04x2-0.04y2 and the cost function is given by
C (x,y)=7x +9y +18,000 where x is the number of type A toy trains produced and
y is the number of type B toy trains produced. Find the profit function P (x,y) and P (250, 500)
Fig: 1