1/12+1/20+1/30+1/42+1/56+1/72+1/90这道题怎样解

问题描述:

1/12+1/20+1/30+1/42+1/56+1/72+1/90这道题怎样解

把他拆成1/3-1/4+1/4-1/5.......+1/8-1/9+1/9-1/10=1/3-1/10
就是这样算的你会了吧