4. Consider the following linear programming problem: Minimize: C = 13x1 + 12x2 subject to: x1 - x2 2 x1 + x2 7 x1 0, x2 0 4.1 Form the matrix A, using the coefficients and constants in the problem constraints and objective function. 4.2 Find AT. 4.3 State the dual problem. 4.4 Use the simplex method to solve the dual problem. 4.5 Read the solution of the minimization problem from the bottom row of the final simplex tableau.