1/21+505/2727+131313/272727+35353535/27272727

问题描述:

1/21+505/2727+131313/272727+35353535/27272727
要简便的!

1/21+505/2727+131313/272727+35353535/27272727=1/21+(5*101)/(27*101)+(13*10101)/(27*10101)+(35*1010101)/(27*1010101)=2