Maximize linear programming using linprog

I have to maximize the function given below: f(x,y) = 150x+175y; subject to

7x + 11y<=77;

10x + 8y<=80;

x>=9;

y<=6;

x>=0;

y>=0;

I tried to find out the value using linprog() function, but i am getting some absurd values:

[X,val]=linprog([-150 -175],[7 11;10 8;1 0;0 1],[77;80;9;6],[],[],[0 0]);

X =

    4.8889
    3.8889

val =

-1.4139e+03

Where did i go wrong? Any help would be really appreciated.

Answer 1

[Torsten]

[X,val]=linprog([-150 -175],[7 11;10 8;-1 0;0 1],[77;80;-9;6],[],[],[0 0],[Inf Inf]);

Best wishes

Torsten.

[Stanislav Kubis]

Great comment! I would only add that the minus is for the equations as the function is trying to maximize but the contraints are still having the wrong sign.