1/2+1/3+1/4+1/5+1/6+1/7+1/8+1/9
=(1/2+1/4+1/8)+(1/3+1/6+1/9)+(1/5+1/7)
=7/8+11/18+12/35
=1又35/72+12/35
=1又2089/2520
拜托啊 这个问题你已经问了三次了 答案是2520/4609
1/2+1/3+1/4+1/5+1/6+1/7+1/8+1/9
=(1/2+1/3+1/6)+(1/5+1/7+1/9)+(1/4+1/8)
=1+143/315+3/8
=1+2089/2520
=4609/2520