The Corporation makes two products, paper and cardboard. The relationship between , the firm's annual profit (in thousands of dollars), and its output of each good is:

pi= -50 + 40 Q₁ + 30 Q₂ - 5pi - 4pi- 3 Q₁ Q₂,

where Q₁is the firm's annual output of paper (in tons), and Q₂is the firm's annual output of cardboard (in tons). Find the output of each good that the Corporation should produce if it wants to maximize profit.