先将原题转化为标准模式,令z=-f,添加松弛变量x3,x4max z = 2x1+3x2+0x3+0x4st. x1 + x2 + x3 = 2 4x1 +6x2 + x4 = 9建立初始单纯形表 cj 2 3 0 0 cB xB b x1 x2 x3 x4 θ 0 x3 2 1 1 1 0 0 x4 9 4 6 0 1 σj 2 3 0 0将x2作为入基变量,求得θ为2, 3/2写入上表 cj 2 3 0 0 cB xB b x1 x2 x3 x4 θ 0 x3 2 1 1 1 0 2 0 x4 9 4 6 0 1 3/2 σj 2 3 0 0将x4作为离基变量,重新计算单纯形表 cj 2 3 0 0 cB xB b x1 x2 x3 x4 θ 0 x3 1/2 1/3 0 0 -1/6 3 x4 3/2 2/3 1 0 1/6 σj 0 0 0 -1/2存在非基变量x1的检验数σj=0,因此该题有无穷多最优解其中一个最优解是x1=0,x2=3/2得到max z = 9/2得到min f = -9/2