| 1/3 - 1/2 | + | 1/4 - 1/3 | + | 1/5 - 1/4 | …… + | 1/2009
来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/11/13 01:40:41
| 1/3 - 1/2 | + | 1/4 - 1/3 | + | 1/5 - 1/4 | …… + | 1/2009 - 1/2008|
| 1/3 - 1/2 | + | 1/4 - 1/3 | + | 1/5 - 1/4 | …… + | 1/2009 - 1/2008|
= 1/2-1/3 +1/3- 1/4 + 1/4 - 1/5 …… + 1/2008 - 1/2009
=1/2+[(-1/3)+1/3]+[(-1/4)+1/4]+……+[(-1/2008)+1/2008]-1/2009
=1/2+0+0+……+0-1/2009
=1/2-1/2009
=2007/4018
= 1/2-1/3 +1/3- 1/4 + 1/4 - 1/5 …… + 1/2008 - 1/2009
=1/2+[(-1/3)+1/3]+[(-1/4)+1/4]+……+[(-1/2008)+1/2008]-1/2009
=1/2+0+0+……+0-1/2009
=1/2-1/2009
=2007/4018
| 1/3 - 1/2 | + | 1/4 - 1/3 | + | 1/5 - 1/4 | …… + | 1/2009
|1/3+(-1/2)|+|1/4+(-1/3)|+|1/5+(-1/4)|+……+|1/2010+(-1/2009)|
1/1×2+1/2×3+1/4×5+……+1/2009×2010
1-1/1*2-1/2*3-1/3*4-1/4*5……-1/2008*2009的值
1/1*2+1/2*3+1/3*4+1/4*5……+1/2009*2010
1+(1/2-1)+(1/3-1/2)+(1/4-1/3)+(1/5-1/4)+…+(1/2009-1/2008)+(1
求 1/2+1/(2*3)+1/(3*4)+1/(4*5)+……+1/(2008*2009)的值
(1-1/3)*(1-1/4)*(1-1/5)*……*(1-1/2009)*2009=?找规律,巧计算
1-2+3-4+5……2009-2010
(1+3+5+…+2009)-(2+4+6…+2010)
计算:-1+2-3+4-5……-2009+2010
1+2+3+4+5+6……+2009+2010