1/20+1/30+1/42+1/56+1/72+1/90

来源：学生作业帮助网编辑：作业帮时间：2024/11/05 13:43:40

1/20+1/30+1/42+1/56+1/72+1/90
1/20+1/30+1/42+1/56+1/72+1/90

1/20+1/30+1/42+1/56+1/72+1/90
1/20+1/30+1/42+1/56+1/72+1/90
=1/4*5+1/5*6+1/6*7+1/7*8+1/8*9+1/9*10
=1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10
=1/4-1/10
=3/20

1/20+1/30+1/42+1/56简便计算, 1/20+1/30+1/42+1/56=1/20+1/30+1/42+1/56= 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 1/2+1/6+1/12+1/20+1/30+1/42+1/56 简算 1/2+1/6+1/12+1/20+1/30+1/42+1/56简算, 1/12+1/20+1/30+1/42+1/56+1/72+1/90 简便运算：1/2+1/6+1/12+1/20+1/30+1/42+1/56 2/1+6/1+12/1+20/1+30/1+42/1+56/1=? 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 - 1/12 - 1/20 - 1/30 - 1/42 - 1/56怎么算 1/2+1/6+1/12+1/20+1/30+1/42+1/56 1/2-1/6-1/12-1/20-1/30-1/42-1/56等于多少 2/1+6/1+12/1+20/1+30/1+42/1+56/1= 1/2+1/6+1/12+1/20+1/30+1/42+1/56= 1/2+1/6+1/12+1/20+1/30+1/42+1/56 1/2+1/6+1/12+1/20+1/30+1/42+1/56