Consider following linear programming problem
maximize Z= x1 + X2
subject to
X1 + 2x2 < 6
5x1+ 3x2 ≤ 12
X1, X2 ≥ 0
a). Solve the model graphically
b). Indicate how much slack resource is available at the optimal solution point
c). Determine the sensitivity range for objective function X₁ coefficient (c₁)