Consider the following problem.

Minimize Z  2x1  x2  3x3, subject to 5x1  2x2  7x3  420 3x1  2x2  5x3  280 and x1  0, x2  0, x3  0.

I

(a) Using the two-phase method, work through phase 1 step by step.

C

(b) Use a software package based on the simplex method to formulate and solve the phase 1 problem.

I

(c) Work through phase 2 step by step to solve the original problem.

C

(d) Use a computer code based on the simplex method to solve the original problem.