第1个回答 推荐于2016-05-27
1+1/3-7/12+9/20-11/30+13/42-15/56
=1+1/3-(1/3+1/4)+(1/4+1/5)-(1/5+1/6)+(1/6+1/7)-(1/7+1/8)
=1-1/8
=7/8
追问能有解释吗
追答7/12=1/3+1/4
9/20=1/4+1/5
13/42=1/6+1/7
15/56=1/7+1/8
追问
相似回答
1+1/3-7/12+9/20-11/30+13/42-15/56
=1+1/3-(1/3+1/4)+(1/4+1/5)-(1/5+1/6)+(1/6+1/7)-(1/7+1/8)
=1-1/8
=7/8
追问能有解释吗
追答7/12=1/3+1/4
9/20=1/4+1/5
13/42=1/6+1/7
15/56=1/7+1/8
追问