Hello Guys! I have this assigment in mathematics: You mix three Nirtophospor manure. Mixture A contains 70% nitrogen and 30% phospor, mixture B contains 40% nitrogen and 60% phospor and mixture C contains 20% nitrogen and 80% phospor. You have 3000 tons nitrogen and 7000 tons phospor. 1 ton of mixture A gives 420$, 1 ton of mixture B gives 600$ and 1 ton of mixture C gives 640$. The problem is to maximize the income. So now I have to set up the problem as an linear programming, so that I can solve it with the simplex method, any ideas on how to set the function and the constrains up?

Try assigning variables to the amount of nitrogen and phosphor you use.
n1 = nitrogen in mixture a
n2 = nitrogen in mixture b
etc
Then make inequalities out of those.