Given this Linear Programming Model: (25 points)

Max Z = 12x + 16y (beneficio)

calle

(1) 10x + 20y < 140

(2) 20x + 16y < 180

(3) 12x + 12y < 120

(4) x, y > 0

(a) Solve the problem by the graphical method.

(b) What would be the optimal solution if the objective function had been 16x + 8y?

(c) What would be the optimal values if the constraint had been (3) 12x + 12y < 180 instead of

(3) 12x + 12y < 120?