1/6+1/12+1/20+1/30+1/42+1/52+1/72

来源：学生作业帮助网编辑：六六作业网时间：2024/11/16 07:49:22

1/6+1/12+1/20+1/30+1/42+1/52+1/721/6+1/12+1/20+1/30+1/42+1/52+1/721/6+1/12+1/20+1/30+1/42+1/52+1/72=

1/6+1/12+1/20+1/30+1/42+1/52+1/72
1/6+1/12+1/20+1/30+1/42+1/52+1/72

1/6+1/12+1/20+1/30+1/42+1/52+1/72
=1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9
=1/2-1/9
=7/18