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运筹学课后习题答案

第一章 线性规划及单纯形法1.用X j (j=1.2…5)分别代表5中饲料的采购数,线性规划模型:12345123412341234min 0.20.70.40.30.8.3267000.50.2300.20.8100(1,2,3,4,5,6)0j z x x x x x st x x x x x x x x x x x x x x x x j =+++++++≥+++≥+++≥=≥555 +18 +2 0.5+2 2.解:设123456x x x x x x x 表示在第i 个时期初开始工作的护士人数,z 表示所需的总人数,则123456161223344556min .607060502030(1,2.3.4.5.6)0i z x x x x x x st x x x x x x x x x x x x x i =++++++≥+≥+≥+≥+≥+≥=≥ 3.解:设用i=1,2,3分别表示商品A ,B ,C ,j=1,2,3分别代表前,中,后舱,Xij 表示装于j 舱的i 种商品的数量,Z 表示总运费收入则:111213212223313233111213212223313233112131122232132333112131max 1000()700()600().6001000800105740010575400105715008652000z x x x x x x x x x st x x x x x x x x x x x x x x x x x x x x x =++++++++++≤++≤++≤++≤++≤++≤++≤ 122232132333112131122232132333122232112131132333865300086515008650.158658650.158658650.18650(1,2.3.1,2,3)ij x x x x x x x x x x x x x x x x x x x x x x x x x i j ++≤++≤++≤++++≤++++≤++≥== 5. (1)Z = 4(2)12121212max .6101207051038z x x st x x x x x x =++≤+≥≤≥≤≥ 解:如图:由图可得: **(10,6)16T x Z == ; 即该问题具有唯一最优解*(10,6)Tx =(3)无可行解(4)12121212max 56.22232,0z x x st x x x x x x =+-≥-+≤≥ 如图:由图知,该问题具有无界解。

6(1)''"1234456'"12344'"123445'"123446'"'1234456max 3425500.22221436z x x x x x x x st x x x x x x x x x x x x x x x x x x x x x x x x =-+-++++-+-=+-+-=++-+=≥ -2 + -2- ,,,,,,0(2)'''"12334''"1233''"12334'"12334max 22330.46z x x x x x st x x x x x x x x x x x x x x =+-++++-=+-+=≥ 2+ ,,,,07.1)系数矩阵A :364)120C ⎛⎫⎪- ⎪ ⎪-⎝⎭=12345612363008102 0=(p p p p p p 30000种组合1123112368145403B P P P B ==-=-≠1 ;可构成基。

求B 的基本解,∴(B ,b )=040⎛⎫⎛⎫⎪ ⎪- ⎪ ⎪ ⎪ ⎪⎝⎭⎝⎭123691008110=0116/33001-7/6∴ y 1=(0,16/3,-7/6,0,0,0)T同理y 2=(0,10,0,-7,0,0)T y 3=(0, 3,0,0,7/2,0)T y 4=(7/4,-4,0,0,0,21/4)T y 5=(0,0,-5/2,8,0,0)Ty 6=(0,0,3/2,0,8,0)T y 7=(1,0,-1/2,0,0,3)T y 8=(0,0,0,3,5,0)T y 9=(5/4,0,0,-2,0,15/4)Ty 10=(0, 3,-7/6,0,0,0)T y 11=(0,0,-5/2,8,0,0)Ty 12=(0,0,-5/2,3,5,0)T y 13=(4/3,0,0,0,2,3/4)Ty 14=(0,10,0,-7,0,0)T y 15=(0, 3,0,0,7/3,0)Ty 16=(0,0,3/2,0,8,0)T基可行解:(每个x 值都大于0),(y 3,y 6,y 8,y 12,y 13,y 15,y 16) 最优解:(y 3,y 6, y 15,y 16) Z max =3[p 2 p 3 p 4],[p 2 p 3 p 5],[p 3 p 4 p 5],[p 2 p 4 p 5]为奇异,∴只有16个基。

246C =8.基的定义10621350314B ==-≠ ∴X 1 X 2 X 3所对应的列向量可以构成基B 由 X 1 X 2 X 3 列向量构成 = 106213314⎡⎤⎢⎥⎢⎥⎢⎥⎣⎦ N 由 非基变量对应的向量构成 =354120⎡⎤⎢⎥⎢⎥⎢⎥⎣⎦(B ,b )= 106102131314⎡⎤⎡⎤⎢⎥⎢⎥→⎢⎥⎢⎥⎢⎥⎢⎥⎣⎦⎣⎦10-13/5 4 00 37/520013/5 ∴B 对应的基解:(-13/5,37/5,0,0,3/5)9.解:(1)由图知:**(1,3/2)35/2;T x Z ==; 单纯形法:化为标准形如下: 12123124max 105.349528i z x x st x x x x x x =+++=++= C 10 5 0 0b C B X B X 1 X 2 X 3 X R 0 X 3 3 4 1 0 9 0 X R 5 2 0 1 8 检验数 10 5 0 0 0 0 X 3 0 14/5 1 -3/5 21/5 10 X 1 1 2/5 0 -1/5 8/5 检验数 0 1 0 -2 -16 5 X 2 0 1 5/14 -3/14 3/2 10 X 1 1 0 -1/7 3/7 0 检验数 0 0 -5/14-25/14-35/2所以:**(1,3/2)35/2;T x Z ==; 其中:(0,0)(8/5,0)(1,3/2)A B C −−−→−−−→−−−→对应T 对应T 对应T (0,0,9,8)(8/5,0,21/5,0)(1,3/2,0,0)9.2)∴A 点最大 Z= 8123412312max 200.3515224(1,2,3,4)0i z x x x x st x x x x x x x i =-++++=++==≥4 6 0点(0,0,15,24)A 点(4,0,3,0) Zmax=810.解1)要使A (0,0)成为最优解则需C ≤0且d ≤0;2)要使B (8/5,0)成为最优解则C ≥0且d=0或C>0且d<0或C/d ≥5/2且Cd>0; 3)要使C (1,3/2)成为最优解则-5/2≤-C/d ≤-3/4且Cd>0;即5/2≥C/d ≥3/4且Cd>0;4)要使D (0,9/4)成为最优解则C<0且d>0或C=0,d>011.(1)化为标准型:1231234123123max 2.36021020(1,2,3,4,5,6)0z x x x st x x x x x x x x x x x x x i =-++++=-++=+-+==≥56 **(,);T x Z ==155,0; 25(2)123456712341231323max 235.223122286164312(1,2,3...7)0i z x x x x x x x st x x x x x x x x x x x x x x x i =+++++++++=+++=++=++==≥5670000 4 **(1,3/2)33/2;T x Z ==,1,1,0,0; (3)标准型: 12313212max 35.4212218z x x st x x x x x x x =++=+=++=45 3 **();T x Z ==2,6; 36 (4)标准型''"'"'"12344556678910'"'"144667'"123668'"'"135********'"'123445max 0.93422222264312z x x x x x x x x x x Mx Mx x st x x x x x x x x x x x x x x x x x x x x x x x x x x x x x =+--+-+-+---++-+-+=+-+-+=+-++-+=++= ,,,,,,"'"56678910x x x x x x ≥,,,,,,0(5)12341234123123max 62108.564420328252310(1,2,3,4)0j z x x x x st x x x x x x x x x x x x x j =++++--≤-++≤-++≤=≥44 5 4 解:标准化:12341234512361237max 62108.564420328252310(1,2,3,4,5,6,7)0j z x x x x st x x x x x x x x x x x x x x x x j =++++--+=-+++=-+++==≥44 5 4 由表可得, 70k p σ>0≤且因此问题的解无界。

(6)化为:标准形:Z ‘=-Z12314624634max .425233265(1,2,3,4,5,6)0i z xx x x st x x x x x x x x x x x x i =----=++=++==≥‘556 - + - 44017207/244722/3x x x x x x x -==⎧⎧⎪⎪-=⇒=⎨⎨⎪⎪-=-=-⎩⎩如图:1. 1. X ≥7/2 时,检验数≤0 ,∴最优解:(5,3,5,0,0)T2. 2. 1≤X<7/2时,4-4X<0,-2X+7>0C-x -1 -10 0 0 bC B X B X 1 X 2 X 3 X 4 X 5 X 6 -X X 1 1 0 1/3 -10/3 -5/3 0 20/3 -1 X 2 0 1 -1/6 5/3 -13/6 0 13/6 0X 6 00 1/61/3-5/615/6 检验数 0X/3-7/6 -10X/3+5/3 -5X/3-13/6 020X/3+13/6 **(20/313/60005/6)20/313/6;T x Z X ==+,,,,,; 3. X <-3/2时 4-4X>-2X+7>0 C-x -1-1 0 0 0 bC B X B X 1 X 2 X 3 X 4 X 5X 6 -X X 1 1 2 0 0 -6 0 11 -1 X 2 0 1/2 0 1 -3/2 1/2 3/2-1X 3 0-110 -252 检验数 02x-2 0 0-6X-2 511X+24.-3/2≤X <1; -2X+7>4-4X>0 C-x -1 -10 0 0 bC B X B X 1 X 2 X 3 X 4 X 5 X 6 -X X 1 1 0 0 -10/3 -5/3 0 20/3 -1 X 2 0 1 0 5/3 -13/6 0 13/6 -1X 6 00 11/3-5/615/6 检验数X/3-7/6 -10X/3+5/3 -5X/3-13/620X/3+13/610/35/301/25/313/6013/1010/35/35/313/6 2.3x x x x x x x -+==⎧⎧⎪⎪--=⇒=-⎨⎨⎪⎪-+=--=⎩⎩1)1/2≤X < 1 ,所有检验数 <0∴**(20/3,13/6,0,0,0,5/6)20/313/6;T x Z X ==+; (1/2≤X< 2)-1.3≤X <1/2时 C -x -1 -1 0 0 0 bC B X B X 1 X 2 X 3 X 4 X 5X 6-X X 1 1 2 0 0 -6 00 11 0 X 4 0 3/5 -1/10 1 -13/10 00 13/10X 6 0-1/51/50 -2/5 11 2/5 检验数 02X-1 -1-6X11X1 0≤X <1/2时, 检验数<0∴**(11,0,0,13/10,0,2/5)11;T x Z X ==; (0≤X ≤1/2) 2-1.3≤X <0时, -6X >0又 X 5列的系数< 0 ,所以解无界 3) -1.5≤X<-1.3时,同表(A )-6X >0 ,又 X 5的列的系数<0,所以解无界(7)123123123123123max 64.221320217123z x x x st x x x x x x x x x x x x =++-++≤-+≤++≤≥≥≥ 4 ,,解:化为标准形:123101112123412351236171028113912max 64.221320217123i z x x x Mx Mx Mx st x x x x x x x x x x x x x x x x x x x x x x =++----+++=-++=+++=-+=++=++= 4 0(1,2,3...11)i ≥=即:**(/,/);T x Z ==72214,3; 47 为最优解,但该问题具有无穷多最优解(8)12335673562316367max 33.3621006(1,2,...7)0j z x x x x x x x st x x x x x x x x x x x x i =-+-+--++=+-=-+=++==≥4 解:化为标准形:123356711356231636711max 33.3621006(1,2,...)0z x x x x x x x x x x x st x x x x x x x x x x x x x x x x i =-+-+------+++=+-+=-++=+++==≥891084910M M M M 11**(0,2,6,0,12,0,0))4;T x Z =-=; 12.(1)解: 标准形: 112378912347138236max 22.620(1,2,3...9)0z x x x Mx Mx Mx st x x x x x x x x x x x x x x i =-+---++-+=-+-+=--+==≥59 2 2得一辅助问题:78912347138236max .620(1,2,3...9)0j w Mx Mx Mx st x x x x x x x x x x x x x x i =---++-+=-+-+=--+==≥59 2 *********56/5,16/5,8/5,0;0;(6/5,16/5,8/5,0,0,0)Tx x x x x x x x w x ==========1234789其最优解为其原问题的初始基本解可行解(2)大M 法,先化为标准形:Z ‘=-Z123141212max 400.24336z x x x x Mx Mx st x x x x x x x x x x =--++--++=++=++=‘4564536 4 - 二阶段法:引入人工变量 X 5 X 6 得原问题的一个辅助问题:141212max .24336w x x st x x x x x x x x x x =--++=++=++=564536 4 - *******52,1,5,0;0;(2,1,5,0,0,0)Tx x x x x x w x ========12346其最优解为其原问题的初始基本解可行解(3)12312312min 23.42826(1,2,3)0j z x x x st x x x x x x j =-+++≥+≥=≥ 3 标准形:'12378123471258min 23.42826(1,2,3...8)0j z x x x Mx Mx st x x x x x x x x x x j =-+---++-+=+-+==≥ 3 (6)两阶段法:78123471258max .42826(1,2,3...8)0z x x st x x x x x x x x x x j =--++-+=+-+==≥ 3 ********4/5,9/5,0;0;x x x x x x x w =======8其最优解为由表知此题为解无界; (4)123123123123max 101512.5395615155(1,2,3)0j z x x x st x x x x x x x x x x i =++++≤-++≤++≥=≥ 2 化为标准形:12371234123512367max 101512.5395615155(1,2,3...7)0z x x x Mx st x x x x x x x x x x x x x x i =++-+++=-+++=++-+==≥ 2 13.(1)100b σ≤≠ ; (2)100,0σαα≤<<12 , (3)0,0,0,0d ααα≥<<≥11216.13,5[0051]0[025]1020[01/551]50[0150]03[005]14/5x x b b a a g g f f e e ∴-⨯+⨯==⎧⎧⎪⎪-⨯+⨯=-=⎪⎪⎪⎪-⨯+⨯=⇒=-⎨⎨⎪⎪-⨯+⨯==⎪⎪-⨯+⨯=-=⎪⎪⎩⎩是基,c=0,d=117.解:由表知:(1) d=1,e=0,b=-6,f=1/3,g=0,a=7; (2)由表知所有70,σ≤所以表中给出的是最优解。

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