Maximize P = x + 16y - z
subject to 2x + y + z 14
4x + 2y + 3z 28
2x + 5y + 5z 30
x 0, y 0, z 0
"College" is not the subject of your question. It is algebra.
Did you omit some = signs in lines 2, 3 and 4? If those are three equations, together they determine the values of x, y and z. There can only be one value for P.
The last line
x 0, y 0, z 0
makes no sense; why is it there?