1/3+1/6+1/9+1/12+1/15+1/18 =(1/3+1/15)+(1/6+1/12)+(1/9+1/18) =6/15+3/12+3/18=2/5+1/4+1/6 =24/60+15/60+10/60 =49/60 分开找公共因数 再相加
1/3+1/6+1/9+1/12+1/15+1/18 =(1/3+1/15)+(1/6+1/12)+(1/9+1/18) =6/15+3/12+3/18 =2/5+1/4+1/6 = 24/60+15/60+10/60 =49/60 这种不是满简单的
1/3+1/15=6/15,1/6+1/12=1/4,1/9+1/18=1/66/15+1/4+1/6=6/15+5/12=49/60等于六十分之四十九
1/3+1/6+1/9+1/12+1/15+1/18=(1/3+1/15)+(1/6+1/12)+(1/9+1/18)=6/15+3/12+3/18=2/5+1/4+1/6=24/60+15/60+10/60=49/60