用单纯形法表格形式解下列线性规划问题 max z=3x1+5x2 s.t. x1 ≤ 8 2x2 ≤ 12 3x1+4x2 ≤ 36 x1, x2 ≥ 0 2. 写出下列线性规划的对偶问题 (1) max z=2x1+x2+x3 s.t. x1+ x2+x3 ≤ 10 x1+5x2+x3 ≤ 20 x1,x2,x3≥0 (2) min f=4x1+4x2+2x3 s.t. 0.5x1+ 2x2+ 2x3 ≥ 100 4x1+ 6x2 +3x3 ≥ 200 x1,x2,x3 ≥ 0 3.写出下列线性规划的对偶问题 (1) max z=x1+2x2+5x3 s.t. 2x1+3x2+x3 ≥ 10 3x1 + x2 +x3 ≤ 50 x1 + x3 =20 x1,x2≥0, x3无非负约束 (2) min f=x1+3x2+2x3 s.t. x1+2x2+3x3 ≥ 6 x1 - x2 +2x3 ≤ 3 -x1 + x2 + x3 = 2 x1≥0, x2无非负约束, x3≤0