简便计算:7/11+5/9+4/9+4/11

问题描述:

简便计算:7/11+5/9+4/9+4/11

=(7/11+4/11)+(5/9+4/9)
=1+1=2

(7/11+4/11)+(4/9+5/9)=2

=(7/11+4/11)+(5/9+4/9)=1+1=2

=(7/11+4/11)+(5/9+4/9)
=1+1
=2

=(7/11+4/11)+(5/9+4/9)=2