Solve the following linear programming problem with the simplex algorithm:
Maximize Z = 2x1 - x2 + x3
Subject to:
3x1 + x2 + x3 ≤ 60
x1 - x2 + 2x3 ≤ 10
x1x2 - x3 ≤ 20
x1, x2, x3 ≥ 0
a) x1 = 10, x2 = 30, x3 = 20
b) x1 = 20, x2 = 10, x3 = 30
c) x1 = 15, x2 = 25, x3 = 10
d) x1 = 25, x2 = 15, x3 = 25