1x1-2x2+3x3-4x4……-2004x2004+2005x2005托式最好马上就要,x是乘号的意思x是乘号的意思啊!老师说=于2009110 托式啊,不然…………汗,

来源：学生作业帮助网编辑：作业帮时间：2024/11/16 16:33:22

1x1-2x2+3x3-4x4……-2004x2004+2005x2005托式最好马上就要,x是乘号的意思x是乘号的意思啊!老师说=于2009110 托式啊,不然…………汗,
1x1-2x2+3x3-4x4……-2004x2004+2005x2005
托式最好马上就要,x是乘号的意思
x是乘号的意思啊!老师说=于2009110 托式啊,不然…………汗,

1x1-2x2+3x3-4x4……-2004x2004+2005x2005托式最好马上就要,x是乘号的意思x是乘号的意思啊!老师说=于2009110 托式啊,不然…………汗,
前两项 1x1-2x2 可看成 1^2(1的平方)-2^2,(2-1)^2-2^2,
拆开,(2^2+1^2-2x2x1)-2^2,2^2+1^2-2x2x1-2^2,1^2-2x2x1.
后两项 3x3-4x4 可看成 (4-1)^2-4^2,
4^2+1^2-2x4x1-4^2,1^2-2x4x1.
同理,到 ……-2004x2004 时,有了2004/2=1002项,
所以1x1-2x2+3x3-4x4……-2004x2004
=1^2-2x2x1+1^2-2x4x1+……+1^2-2x2004x1
=1x1002-2x(2+4+……+2004)
=1002-2x(2+4+……+2004)
2+4+……+2004有1002项 ,你看,2+2004=2006 ,4+2002=2006,
所以 2+4+……+2004=2006x1002/2.
总共
1x1-2x2+3x3-4x4……-2004x2004+2005x2005
=1002-2006x1002+2005x2005
=1002-205224+410025
=1002+204801
=205803.
不懂得在问我啊,在.

运筹学……对偶问题.maxz=x1+2x2+3x3+4x4-x1+x2-x3-3x4=56x1-7x2+3x3-5x4 用初等行变换来解下列线性方程组（1）2x1-x2+3x3=3 3x1+x2-5x3=0 4x1-x2+x3=3 x1+3x2-13x3=-6(2) x1-2x2+x3+x4=1 x1-2x2+x3-x4=-1 x1-2x2+x3-5x4=5(3) x1-x2+x3-x4=1 x1-x2-x3+x4=0 x1-x2-2x3+2x4=-1/2 用克拉默法则解下列方程组 x1-2x2+3x3-4x4=4 x2-x3+x4=-3 x1+3x2+2x4=1 -7x2+3x3+x4=3x1-2x2+3x3-4x4=4x2-x3+x4=-3 x1+3x2+2x4=1 -7x2+3x3+x4=3 1x1!+2x2!+3x3!+4x4!.nxn! X1-X2-3X3+X4=1 X1-X2+2X3-X4=3 2X1-2X2-11X3+4X4=0 4X1-4X2+3X3-2X4=10 用消元法解线性方程组非齐次线性方程组求解.x1+x2+2x3+3x4=1 2x1+3x2+5x3+2x4=-3 3x1-x2-x3-2x4=-4 3x1+5x2+2x3-2x4=-10 求方程组X1-3X2-2X3-X4=1 3X1-8X2-4X3-X4=0 -2X1+X2-4X3+2X4=1 -X1-2X2-6X3+X4=2的解求线性方程组{X1-3x2-2x3-X4=1;3X1-8X2-4X3-X4=0;-2X1+X2-4X3+2X4=1;-X1-2X2-6X3+X4=2的一般解. 讨论2X1+X2-X3+X4=1 3X1-2X2+2X3-3X4=2 5X1+X2-X3+2X4=-1 2X1-X2+X3-3X4=4的解的情况 {2X1 -X2 -X3 +X4 = 2{X1 +X2 -2X3 +X4 = 2{4X1 -6X2 +2X3 -2X4 = 4{X1 +4X2 -3X3 +2X4 = 1 求非齐次线性方程组的通解x1+3x2+5x3-4x4=1x1+3x2+2x3-2x4+x5=-1x1-2x2+x3-x4-x5=3x1+2x2+x3-x4-x5=3 求线性方程组x1-3x2-2x3-x4=1,3x1-8x2-4x3-x4,-2x1+x2-4x3+2x4=1,-x1-2x2-6x3+x4= x1-x2+x3=1 x2-x3+x4=2 x3-x4+x5=3 x4-x5+x1=4 x5-x1+x2=5 求x1,x2,x3,x4,x5 下列方程组如何解 2x1+x2-2x3+3x4=1 3x1+2x2-x3+2x4=4 3x1+3x2+3x3-3x4=52x1+x2-2x3+3x4=13x1+2x2-x3+2x4=43x1+3x2+3x3-3x4=5如何解这个线性方程组，因为不太懂。线性方程组 X1+X2+X3+X4=0,2X1+X2+X3+2X4=0,3X1+2X2+4X3+4=1 ｛2X1-X2+3X3=33X1+X2-5X3=04X1-X2+X3=3X1+3X2-13X3=-6{X1-2X2+3X3-4X4=4X2-X3+X4=-3X1+3X2-3X4=1-7X2+3X3+X4=-3 用列主元Gauss消元法解线性方程组{-x2-x3+x4=0,x1-x2+x3-3x4=1,2x1-2x2-4x3+6x4=-1,x1-2x2-4x3+x4=-1 求线性方程组的基础解系及通解x1+x2+x3+x4=13x1+2x2+x3+x4=-3x2+2x3+2x4=65x1+4x2+3x3+3x4=-1