王文平
幼苗
共回答了17个问题采纳率：94.1% 举报
1/4-9/20+11/30-13/42+15/56
=1/4-(1/4+1/5)+(1/5+1/6)-(1/6+1/7)+(1/7+1/8)
=1/4-1/4-1/5+1/5+1/6-1/6-1/7+1/7+1/8
=1/8
1年前
追问
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我的宝贝小怪
举报
=1/4-(1/4+1/5)+(1/5+1/6)-(1/6+1/7)+(1/7+1/8) =1/4-1/4+1/5-1/5+1/6-1/6+1/7-1/7+1/8 =1/8 因该是这个吧
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