(a) Show that cycling occurs when solving the problem using the simplex method. (b) Use Brand's Rule to terminate cycling and obtain an optimal solution, if one exists. 8. Minimize z = x1 + 7x2 + :4:3 + 2x4 subject to xl+ x2+ X34\" x4+x5 = l 11 5 5x17x25x3+9x4 +x6 -0 l 3 1 5x1\" 5x25x3+ 34 +x7=0 XII-20, j=1,...,7 (due to K. T. Marshall and J. W. Suurballe)