1x2+2x3+3x4+4x5+······98x99+99x100=?
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
计算1x2+2x3+3x4+4x5+...+99x100
一定要帮我啊!(1/1x2)+(1/2x3)+(1/3x4)+(1/4x5)+.+(1/99x100)=?
设实数x1,x2,x3,x4,x5均不小于1,且x1·x2·x3·x4·x5=729,则max{x1x2,x2x3,x3
1x1-2x2+3x3-4x4+5x5-6x6.-100x100+101x101
1x2+2x3+3x4+4x5······100x101答案是几?
简便计算1/2+1/2x3+1/3x4+1/4x5+...+1/99x100
求齐次线性方程组x1+2x2+x3+x4+x5=1 2x1+4x2+3x3+x4+x5=2 -x1-2x2+x3+3x4
解方程组X2+X3+X4=1 X1+X2+X3=5 X3+X4+X5=-5 X4+X5+X1=-3 X5+X1+X2=2