①1+1\2+1\6+1\12=1\20+1\30+1\42+1\56+1\72= ②1-1\2-1\4-1\8-1\1
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+190+1/110=?
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90=
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90=多少
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90=______
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+.1/9900=?
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=?
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=
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/