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=?
1/12+1/20+1/30+1/42+1/56+1/72+1/90=?
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=?
1/2+1/6+1/12+1/20+1/30+1/42+1/56=
1/12+1/20+1/30+1/42+1/56+1/72= 等于多少?
1/6+1/12+1/20+1/30+1/42+1/56=?
1/20+1/30+1/42+1/56
20分之1+30分之1+42分之1+56分之1+72分之1=?
1+1/2+1/6+1/12+1/20+1/30+1/42+1/56+.1/132=
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+190+1/110=?