1-1/2)+(1/2-1/3)+(1/3-1/4).(1/2009-1/2010) = 1-1/2+1/2-1/3+1/3-1/4.1/2009-1/2010答案=2009/2010

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/29 03:11:54
1-1/2)+(1/2-1/3)+(1/3-1/4).(1/2009-1/2010) = 1-1/2+1/2-1/3+1/3-1/4.1/2009-1/2010答案=2009/2010
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1-1/2)+(1/2-1/3)+(1/3-1/4).(1/2009-1/2010) = 1-1/2+1/2-1/3+1/3-1/4.1/2009-1/2010答案=2009/2010
1-1/2)+(1/2-1/3)+(1/3-1/4).(1/2009-1/2010) = 1-1/2+1/2-1/3+1/3-1/4.1/2009-1/2010
答案=2009/2010

1-1/2)+(1/2-1/3)+(1/3-1/4).(1/2009-1/2010) = 1-1/2+1/2-1/3+1/3-1/4.1/2009-1/2010答案=2009/2010
你写的这一步是去括号
然后-1/2+1/2抵消
-1/3+1/3抵消
……
-1/2009+1/2009抵消
所以=1-1/2010=2009/2010

这应该是某个题目的中间过程吧
比如 让你算数列bn=1/n(n+1)从1到2009的和