Maximize earnings = $0.80X1 + $0.40X2 + $1.20X3 ? $0.10X4
subject to: X1 + 2X2 + X3+ 5X4= 150
X2- 4X3 + 8X4 = 70
6X1 + 7X2 + 2X3 ? X4 = 120
X1,X2,X3,X4 = 0
(a) Change these constraints to equalities through adding the appropriate slack, surplus, or artificial variables. Also, add new variables into the problem's objective function.
(b) Set up the complete initial simplex tableau for this problem. Do not attempt to solve.
(c) Give the values for all variables in this initial solution.