Final answer:
To demonstrate graphically that the feasible region is unbounded, plot the given constraints on a graph. To determine if the model has an optimal solution, maximize the objective function within the feasible region.
Step-by-step explanation:
To demonstrate graphically that the feasible region is unbounded, we will plot the given constraints on a graph. The first constraint, -x1 + 3x2 ≤ 30, can be rewritten as 3x2 ≥ x1 - 30. The second constraint, -3x1 + x2 ≤ 30, can be rewritten as x2 ≥ 3x1 - 30. Plotting these inequalities on a graph will show that the feasible region is unbounded.
To determine if the model has an optimal solution, we will maximize the objective function, Z = -x1 + x2, within the feasible region. Since the feasible region is unbounded, the model does not have an optimal solution.