Determine the optimum solution for each of the following LPs using the Simplex Method.
a. Maximize z = 2x1 - 4x2 + 5x3 - 6x4
Subject to
x1 + 4x2 -2x3 +8x4 <=2
-x1 +2x2+3x3+4x4 <=1
x 1 , x2, x3, x4 => 0
b. Minimize z = x1 + 2x2 - 3x3 - 2x4
Subject to
x1 + x2 <=6
2x1 + x2 <=16
x1, x2 => 0