1/30+1/42+1/56+1/72+1/90的最简便算法

来源：学生作业帮助网编辑：作业帮时间：2024/04/30 02:46:41

1/30+1/42+1/56+1/72+1/90的最简便算法
1/30+1/42+1/56+1/72+1/90的最简便算法

1/30+1/42+1/56+1/72+1/90的最简便算法
1/30=1/（5×6）=1/5-1/6
1/42=1/（6×7）=1/6-1/7
……
1/30+1/42+1/56+1/72+1/90
=1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10
=1/5-1/10
=1/10

上式等于：(1/5-1/6)+(1/6-1/7)+(1/7-1/8)+(1/8-1/9)+(1/9-1/10)=1/5-1/10=1/10

1/30+1/42+1/56+1/72+1/90
=1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10
=1/5-1/10
=1/10

1/30+1/42+1/56+1/72+1/90 1/30+1/42+1/56+1/72+1/90 1/30+1/42+1/56+1/72 简算 1/30+1/42+1/56+1/72简便算法 1/30+1/42+1/56+1/72＝简算1/30+1/42+1/56+1/72＝? 1/30+1/42+1/56+1/72= 30分之1+42分之一+56分之1+72分之一 1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72 1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72 1/12+1/20+1/30+1/42+1/56+1/72+1/90 1/12+1/20+1/30+1/42+1/56+1/72+1/90 1/6+1/12+1/20+1/30+1/42+1/56+1/72 简便计算 1/2+1/6+1/20+1/30+1/42+1/56+1/72等于多少? 1/2+1/6+1/20+1/30+1/42+1/56+1/72等于几? 1/6+1/12+1/20+1/30+1/42+1/56+1/72 1/12+1/20+1/30+1/42+1/56+1/72+1/90=? 1/6+1/12+1/20+1/30+1/42+1/56+1/72=?