x3+2x:=2 S. t 2x1+x,+3x=5 ≥0(=1,2,34) (答案:日≤1/2时 0,x2=5,x3=2,x4=0,S1=5 1/2≤6≤1时x1=2,x2=1,x3=0,x4=O,S2=3 6≥1时 26分析下列参数规划问题中,当θ变化时最优解的变化情况 S=45x1+80 6<+∞) 5x1+20x2≤400+ S. t 10x1+15x2≤450+56 x1,x2≥0 (答案:θ<-90时,无可行解 90≤6≤-600/17时x1=0,x2=30+0,S1=2400+ 600 ≤6≤时x1=24+6,S2=2200+210 6≥时 80+O,x2=0,S3=3 ②minS=2x4+8 x1+3x4-x5= 4x-12 x4+3x x≥0=12,345 (答案:6<0时,无可行解 0≤6≤1时x1=20,x2=5-20, 0,x4=1-0,S1=2 1≤6≤3时x1=3-,x2=1+20 0,S2=0 3≤6≤4时x1=x4=0,x2=7,x3=8-26,x5=-3+6,3=-24+86 b>4时,无可行解 27已知线性规划问题: max s=27 s.t.       = + + = + + = 0( 1,2,3,4) 2 3 5 2 2 1 2 4 1 3 4 x j x x x x x x j (答案:  1/ 2 时 0, 5, 2, 0, 5 2 * x1 = x2 = x3 = x4 = S1 = − 1/ 2  1 时 2, 1, 0, , 3 * x1 = x2 = x3 = x4 =  S2 =  1 时 0, 2, 0, 1, 2 2 * x1 = x2 = x3 = x4 = S3 = + ) 26.分析下列参数规划问题中,当  变化时,最优解的变化情况: ① max 45 1 80 2 S = x + x ( −   + ) s.t.       +  + +  + , 0 10 15 450 5 5 20 400 1 2 1 2 1 2 x x x x x x   (答案:   −90 时,无可行解 −90   −600/17 时   3 80 , 2400 3 1 0, 30 * x1 = x2 = + S1 = + 3 356 17 600 −    时 , 2200 21 25 17 24 * x1 = + S2 = + 3 350   时 , 0, 3600 9 5 1 80 * x1 = + x2 = S3 = + ② min 2 4 8 5 S = x + x s.t.         = − + = − + − − = + + − = − 0( 1,2,3,4,5) 3 1 4 12 1 2 3 3 3 4 5 2 5 1 4 5 x j x x x x x x x x x j    (答案:   0 时,无可行解. 0  1 时 2, 5 2, 0, 1 , 2 2 * x1 = x2 = − x3 = x5 = x4 = − S1 = − 1  3 时 3 , 1 2 , 1 , 0, 0 * x1 = − x2 = +  x3 − + x4 = x5 = S2 = 3   4 时 0, 7, 8 2, 3 , 24 8 * x1 = x4 = x2 = x3 = − x5 = − + S3 = − +   4 时,无可行解. 27.已知线性规划问题: max 2 1 2 S = x + x