Consider the following problem.

Maximize Z  x1  2x2  x3, subject to 3x2  x3 120 x1 x2 4x3 80 3x1  x2  2x3 100

(no nonnegativity constraints).

(a) Reformulate this problem so that all variables have nonnegativity constraints.
D,I

(b) Work through the simplex method step by step to solve the problem.
C

(c) Use a computer package based on the simplex method to solve the problem.