| 年级 | 科目 | 问题描述 | 提问时间 |
| 初一 | 数学 | 有理数运算 | 2013-07-29 09:29:05 |
| 1/1×2+1/2×3+1/3×4+``````1/1000×1001 | |||
| 学点点闵老师 2013-07-29 09:36:35 | |||
| 1-1/2+1/2-1/3+...+1/1000-1/1001=1-1/1001=1000/1001 | |||
| 王老师 2013-07-29 09:38:15 | |||
| 1/(1×2)+1/(2×3)+1/(3×4)+1/(4×5)+……+1/(1000×10001) =(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+……+(1/1000-1/1001) =1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+……+1/1000-1/1001 =1-1/1001 =1000/1001 | |||
