Giant Ladders, Inc., wants to maximize its daily total output of large step ladders by producing x₁ of them by a process P₁ and x₂ by a process P₂, where P₁ requires 2 hours of labor and 4 machine hours per ladder, and P₂ requires 3 hours of labor and 2 machine hours. For this kind of work, 1200 hours of labor and 1600 hours on the machines are, at most, available per day. Find the optimal x₁ and x₂.