Consider the Linear Programming Problem \( P \): \[ \text{Minimize } 2x_1 - 5x_2 \] subject to \[ 2x_1 + 3x_2 + s_1 = 12, \] \[ -x_1 + x_2 + s_2 = 1, \] \[ -x_1 + 2x_2 + s_3 = 3, \] \[ x_1 \geq 0, x_2 \geq 0, s_1 \geq 0, s_2 \geq 0, \text{ and } s_3 \geq 0. \] If \[ \left[ \begin{array}{c} x_1 \\ s_1 \\ s_2 \\ s_3 \end{array} \right] \] is a basic feasible solution of \( P \), then \( x_1 + s_1 + s_2 + s_3 = \underline{\hspace{1cm}}. \)
For the linear programming problem: \[ {Maximize} \quad Z = 2x_1 + 4x_2 + 4x_3 - 3x_4 \] subject to \[ \alpha x_1 + x_2 + x_3 = 4, \quad x_1 + \beta x_2 + x_4 = 8, \quad x_1, x_2, x_3, x_4 \geq 0, \] consider the following two statements:
S1: If \( \alpha = 2 \) and \( \beta = 1 \), then \( (x_1, x_2)^T \) forms an optimal basis.
S2: If \( \alpha = 1 \) and \( \beta = 4 \), then \( (x_3, x_2)^T \) forms an optimal basis. Then, which one of the following is correct?
Consider the following regions: \[ S_1 = \{(x_1, x_2) \in \mathbb{R}^2 : 2x_1 + x_2 \leq 4, \quad x_1 + 2x_2 \leq 5, \quad x_1, x_2 \geq 0\} \] \[ S_2 = \{(x_1, x_2) \in \mathbb{R}^2 : 2x_1 - x_2 \leq 5, \quad x_1 + 2x_2 \leq 5, \quad x_1, x_2 \geq 0\} \] Then, which of the following is/are TRUE?