2/1+6/1+12/1+20/1+30/1+...+110/1=多少.
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/07/14 12:21:10
2/1+6/1+12/1+20/1+30/1+...+110/1=多少.
![2/1+6/1+12/1+20/1+30/1+...+110/1=多少.](/uploads/image/z/19796719-31-9.jpg?t=2%2F1%2B6%2F1%2B12%2F1%2B20%2F1%2B30%2F1%2B...%2B110%2F1%3D%E5%A4%9A%E5%B0%91.)
裂项求和即可
2/1+6/1+12/1+20/1+30/1+...+110/1
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+.+(1/10-1/11)
=1-1/11
=10/11
2/1+6/1+12/1+20/1+30/1+...+110/1
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+.+(1/10-1/11)
=1-1/11
=10/11