1/42+1/56+1/72+1/90+1/110=?
1/42+1/56+1/72+1/90+1/110
42/1+1/56+1/72+1/90+1/110
1/42+1/56+1/72+1/90+1/110+1/132=?
42/1 + 56/1 +72/1 + 90/1 + 110/1 + 132/1=?
1/30+1/42+1/56+1/72+1/90+1/110=?
1/20+1/30+1/42+1/56+1/72+1/90+1/110+1/132=?
1/42+1/56+1/72+1/90+1/110+1/132.求简便算法
1\30+1\42+1\56+1\72+1\90+1\110,简便计算
1/30+1/42+1/56+1/72+1/90+1/110简便算法(过程)
1/42+1/56+1/72+1/90+1/110+1/320的简便运算
30分之1+42分之1+56分之1+72分之1+90分之1+110分之1=?
若a=1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110+1/132+1/