申論題

2. (10 points) Reconsider the lincar programming problem in Question I.
  
It turns out that the right-hand side of the fourth constraint is 3 instead of 2. In addition, somehow the maximum number of equations the computer is able to handle is three so let us consider this problem as follows:

where 0≤ x₂ ≤ 3 can be viewed as the explicit bound on the individual variable.

(a) (5points) Only X₃, x₄,x₅ are introduced as the slack variables for the first, second, and third constraints. What is the criteria of the value of x₂ if x₂ is a nonbasic variable?