Consider the following mathematical programming model:
Minimize z = -x₁ - x₂ - x₃ subject to
-x₂ + x₃ ≥ -1
(x₃)/(x₁ + x₂ + x₃) ≤ 0.1
What is the objective function in the given LP model?
1) -x₁ - x₂ - x₃
2) -x₁ - x₂ + x₃
3) -x₁ + x₂ - x₃
4) -x₁ + x₂ + x₃