作业帮1/1X2X3+1/2X3x4+…+1/48X49X50
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/07 05:10:20
1/1X2X3+1/2X3x4+…+1/48X49X50
1/1X2X3+1/2X3x4+…+1/48X49X50
1/1X2X3+1/2X3x4+…+1/48X49X50
1/1X2X3+1/2X3x4+…+1/48X49X50
=（1/1X2-1/2X3+1/2X3-1/3x4+…+1/48X49-1/49X50）÷2
= （1/1X2-1/49X50）÷2
=（1/2-1/2450）÷2
=1224/2450÷2
=306/1225
=1/2x(1/1x2-1/2x3)+1/2x(1/2x3-1/3x4)+……+1/2x(1/48x49-1/49x50)
=1/2x(1/1x2-1/2x3+1/2x3-1/3x4+……+1/48x49-1/49x50)
=1/2x(1/1x2-1/49x50)
=306/1225
1x2x3+2x3x4+...+nxx=?
1/1X2X3+1/2X3x4+…+1/48X49X50
1x2x3+2x3x4+…+n(n+1)
1x2x3+2x3x4+3x4x5+…+8x9x10
1x2X3+2x3X4+3x4X5+…+7X8X9=?
计算1x2x3+2x3x4+…+48x49x50
1/1x2x3+1/2x3x4+.+1/98x99x100 .
1X2X3+2X3X4+.+n(n+1)(n+2)
1x2x3+2x3x4+.+nx(n+1)(n+2)=?
1x2x3+2x3x4+.+n(n+1)(n+2)=?
求和1x2x3+2x3x4+...+n(n+1)(n+2)
1x2x3+2x3x4+3x4x5+.+10x11x12
1x2x3+2x3x4+3x4x5+...+7x8x9=,
1x2x3 2x3x4 3x4x5 .10x11x12,怎么算
求和：1X2X3+2X3X4+3X4X5+...+98X99X100
1/1x2x3+1/2x3x4+1/3x4x51/2x3x4 + 1/3x4x5 + 1/4x5x6 +……+1/99x100x101是 1/（2x3x4）
1x2x3分之1+2x3x4分之1+……+10x11x12分之1等于多少
求和Sn=1x2x3+2x3x4+……+n(n+1)(n+2)