1+×。≥60 70 +×60 St×3+X2≥50 +×5220 X5+×6≥30 1≥0(=1,234,56)Minz=x1+x2+x3+x4+x5+x6 x1+x6 ≥ 60 x1+x2 ≥ 70 x2+x3 ≥ 60 st. x3+x4 ≥ 50 x4+x5 ≥ 20 x5+x6 ≥30 xj ≥ 0 (j=1,2,3,4,5,6)