1/(1*20)+1/(2*3)+1/(3*4).+1/(2009*2010)=?
2020-11-20 125次 反馈错误 加入收藏 正确率 : 100%
题目内容:
1/(1*20)+1/(2*3)+1/(3*4).+1/(2009*2010)=?
优质解答
1/(1*2)+1/(2*3)+1/(3*4).+1/(2009*2010)
=[(1-1/2)+(1/2-1/3)+(1/3-1/4)+...+(1/2009-1/2010)]
=(1-1/2010)
=2009/2010
本题链接: