Linear programming with complex inequalities

I just wanna solve:

min Z=20X+18Y

with

2X+3Y>=10
4X+7Y>=28
X>=0, Y>=0

Answer is X=0, Y=4 and Z=72 How can i use the linprog command but with >= inequalities?

Answer 1

[Torsten]

Multiply the >= inequalities by (-1).

Best wishes

Torsten.

[Nik Sam]

I know that but it doesnt work

[Torsten]

Please show your code.

Best wishes

Torsten.

[Nik Sam]

f=[-20 -18]
A=[-2 -3;-4 -7]
B=[-10 -28]
Aeq=[];
beq=[];
lb=[0 0];
ub=[];
[x,fval,exitflag,output]=linprog(f,A,B,Aeq,beq,lb,ub)

[Torsten]

f=[20 18]

Best wishes

Torsten.