1X1+2X2+3X3+4X4+5X5.+98X98+99X99+100X100=?
1/1x2+1/2x3+1/3x4+1/4x5+.+1/98x99+1/99x100
1/1X2+1/2x3+1/3x4+1/4x5+.+1/98x99+1/99x100求结果!
2/1x2+2/2x3+2/3x4+2/4x5+...+2/98x99+2/99x100
求1x2,2x3,3x4,4x5,……98x99,99x100的倒数和
1x1-2x2+3x3-4x4+5x5-6x6.-100x100+101x101
已知x4+x3+x2+x+1=0,求x100+x99+x98+x97+x96的值.
解方程组X2+X3+X4=1 X1+X2+X3=5 X3+X4+X5=-5 X4+X5+X1=-3 X5+X1+X2=2
求齐次线性方程组x1+2x2+x3+x4+x5=1 2x1+4x2+3x3+x4+x5=2 -x1-2x2+x3+3x4
计算1x2+2x3+3x4+4x5+...+99x100
一定要帮我啊!(1/1x2)+(1/2x3)+(1/3x4)+(1/4x5)+.+(1/99x100)=?
解一道方程组x1+x2+x3=5,x2+x3+x4=1,x3+x4+x5=-5,x4+x5+x1=-3,x5+x1+x2
X1 - X3 - X4 -5X5=0 X1+2X2+3X3+3X4+7X5=0 X1+X2+X3+X4+X5=0 X2