191问答库 > (1⼀2+1⼀4+1⼀6+1⼀8)-(1⼀3+1⼀6+1⼀9+1⼀12)+(1⼀4+1⼀8+1⼀12+1⼀16)-(1⼀5+1⼀10+1⼀15+1⼀20)=

(1⼀2+1⼀4+1⼀6+1⼀8)-(1⼀3+1⼀6+1⼀9+1⼀12)+(1⼀4+1⼀8+1⼀12+1⼀16)-(1⼀5+1⼀10+1⼀15+1⼀20)=

2025-03-04 22:09:21

推荐回答（1个）

回答1：

楼主您好：
（1/2+1/4+1/6+1/8）-（1/3+1/6+1/9+1/12）+（1/4+1/8+1/12+1/16）-（1/5+1/10+1/15+1/20）
=1/2(1+1/2+1/3+1/4)-1/3(1+1/2+1/3+1/4)+1/4(1+1/2+1/3+1/4)-1/5(1+1/2+1/3+1/4)
=(1+1/2+1/3+1/4)(1/2-1/3+1/4-1/5)
=(12+6+4+3)/12*(30-20+15-12)/60
=25/12*13/60
=65/144

祝楼主学习进步