问题描述:
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90=多少
问题解答:
我来补答展开全文阅读
补充回答:
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5, -1/6+1/6-1/7+1/7-1/8+1/8-1/9+1/9, 减1/10,=1-1/10=9/10
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2023-01-11