1\42+1\56+1\72+1\90+1\90简算
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90简算
1/30+1/42+1/56+1/72+1/90
1/42+1/56+1/72+1/90+1/110
42/1+1/56+1/72+1/90+1/110
简算:1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
简算(要有过程)(1)1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110+1/132(2)
简算1/30+1/42+1/56+1/72=?
1/30+1/42+1/56+1/72 简算
1/12+1/20+1/30+1/42+1/56+1/72+1/90=?
(1)1-1/6+1/42+1/56+1/72+1/90
1/12+1/20+1/30+1/42+1/56+1/72+1/90
20/1+30/1+42/1+56/1+72/1+90/1 用简便方法计算.