So far the best ive come up with is
Maximse Z = 16x1 + 14x2 - 2x5
2x1 + 3x2 <= 60 (labour)
0.5x1 + x2 <= 20 (materials)
0.05x1 + 0.075x2 >= 0 (Formula s produced) notsure about this
Like i said it's the disposal amounts I can't work out how to incorporate into the next line. I'm thinkning something along the lines of: x4 - 2x5 <=500.