Minimize subject to
C = 10x1 + 12x2 +28x3
4x1 + 2x2 + 3x3 ≥ 20
3x1 - x2 - 4x3 ≤ 10
x1, x2 , x3 ≥ 0
Problem are mixed. Some can be solved by the methods presented in Sections 6-2 and 6-3, while others must be solved by the big M method.