1/3+1/5+1/7+1/9+1/11 +到1/39 简便计算怎样算
问题描述:
1/3+1/5+1/7+1/9+1/11 +到1/39 简便计算怎样算
答
1/3+1/5+1/7+1/9+1/11 +到1/39
=(1-1/3+1/3-1/5+.1/37-1/39)/2
=(1-1/39)/2
=76/39