4.II.14HOptimizationPart IB, 2003Use the two-phase simplex method to solve the problemminimize5x1−12x2+13x3 subject to 4x1+5x2≤96x1+4x2+x3≥123x1+2x2−x3≤3xi≥0,i=1,2,3\begin{array}{llllll} \operatorname{minimize} & 5 x_{1}-12 x_{2}+13 x_{3} & & \\ \text { subject to } & 4 x_{1}+5 x_{2} & & \leq & 9 \\ & 6 x_{1}+4 x_{2}+ & x_{3} & \geq & 12 \\ & 3 x_{1}+2 x_{2}-x_{3} & \leq & 3 \\ & x_{i} \geq 0, & i=1,2,3 \end{array}minimize subject to 5x1−12x2+13x34x1+5x26x1+4x2+3x1+2x2−x3xi≥0,x3≤i=1,2,3≤≥3912