(1/8+1/9+1/+1/10+1/11)*(1/9+1/10+1/11+1/12)-(1/8+1/9+1/10+1/11+1/12)*(1/9+1/10+1/11)

(1/8+1/9+1/+1/10+1/11)*(1/9+1/10+1/11+1/12)-(1/8+1/9+1/10+1/11+1/12)*(1/9+1/10+1/11)
(1/8+1/9+1/+1/10+1/11)*(1/9+1/10+1/11+1/12)-(1/8+1/9+1/10+1/11+1/12)*(1/9+1/10+1/11)

(1/8+1/9+1/+1/10+1/11)*(1/9+1/10+1/11+1/12)-(1/8+1/9+1/10+1/11+1/12)*(1/9+1/10+1/11)

1/96嗯啊额

令l/8 1/9 1/10 1/11=a，1/9 1/1O 1/11=b，原式化为1/12(a-b)=1/12x1/8=1/96

1/96
1/8+1/9+1/10+1/11+1/12-1/12即可

诶诶诶，你们上面答的人不觉得这题目不完整吗。。。
1/9+1/+1/10
这怎么答么