1 1 1 1 1 ——+——+——+——+```````` —— 2X3 3X4 4X5 5X6 99X100
1x1-2x2+3x3-4x4+5x5-6x6.-100x100+101x101
简便计算1/2+1/2x3+1/3x4+1/4x5+...+1/99x100
计算1x2+2x3+3x4+4x5+...+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!
一定要帮我啊!(1/1x2)+(1/2x3)+(1/3x4)+(1/4x5)+.+(1/99x100)=?
2/1x2+2/2x3+2/3x4+2/4x5+...+2/98x99+2/99x100
求1x2,2x3,3x4,4x5,……98x99,99x100的倒数和
1X2+2X4+3X6+.50X100
1/1X2+1/2X3+1/3X4+1/4X5+1/5X6……1/2007X2008
1x2/1+2x3/1+3x4/1+4x5/1+5x6/1+6x7/1
1/1x2+1/2x3+1/3x4+1/4x5+1/5x6+......1/2008x2009