1/4+1/28+1/70+…1/89698=?
问题描述:
1/4+1/28+1/70+…1/89698=?
答
1/4+1/28+1/70+…1/89698
=1/3×(1-1/4+1/4-1/7+1/7-1/10+...+1/298-1/301)
=1/3×(1-1/301)
=100/301