The corner points of the feasible region determined by the system of linear constraints are (0, 4), (4, 0), (5, 0), (5, 3), (3, 5), (0, 5). Let $Z=x-7y+80.$ The minimum value of Z occurs at :

(5, 0) (0, 5) (3, 5) (5, 3)

(0, 5)