1/1x2x3+1/2x3x4.1/98x99x100拜托了各位

来源：学生作业帮编辑：搜狗做题网作业帮分类：数学作业时间：2024/07/08 21:30:18

1/1x2x3+1/2x3x4+1/3x4x5+.1/98x99x100= =1/2[1/1*2-1/2*3]+1/2[1/2*3-1/3*4]+1/2[1/3*4-1/4*5]+...+1/2[1/98*99-1/99*100] =1/2[1/1*2-1/2*3+1/2*3-1/3*4+1/3*4-1/4*5+...+1/98*99-1/99*100] =1/2[1/2-1/99*100] =1/2*4949/9900 =4949/19800

1/1x2x3+1/2x3x4+1/3x4x5+.1/98x99x100= 1/1x2x3+1/2x3x4+1/3x4x5 求和1x2x3+2x3x4+...+n(n+1)(n+2) 1x2X3+2x3X4+3x4X5+…+7X8X9=? 1x2x3+2x3x4+3x4x5+…+8x9x10 1x2x3+2x3x4+3x4x5+...+7x8x9=, 1x2x3+2x3x4+3x4x5+.+10x11x12 1x2=(1/3)(1x2x3-0x1x2) 3x4=(1/3)(3x4x5-2x3x4) 问1x2x3+2x3x4+. 有理数:1.计算:1/1x2x3+1/2x3x4+1/3x4x5+...+1/98x99x1002.求式子:|x+1|+ 1/1x2x3+1/2x3x4+1/3x4x5+1/4x5x6+.+1/48x49x50= 1/1x2x3+1/2x3x4+1/3x4x5+.+1/11x12x13= 1/1x2x3+1/2x3x4+1/3x4x5+.+1/9x10x11=