Please help me solve this questions

1. solve the linear programming problem. Restrict x 0 and y 0

Maximize F= 2x +9y subject to

x+y 7

2x + y 12

x +3y 15

(x,y) =

F=

2. Find the indicated maximum or minimum value of the objective function in the linear programming problem.

Maximize f= 30x +70y subject to the following

x + 2y 48

x + y 30

2x + y 50

x 0, y 0

F=

3. Graph the solution of inequalities

x + 2y 70

2x + y 77

x + y 63

x 0, y 0