[1/6-(5/14-1/3)]*7/9 简便运算
问题描述：
[1/6-(5/14-1/3)]*7/9 简便运算
答
[1/6-(5/14-1/3)]*7/9
=(1/6+1/3-5/14)*7/9
=(1/2-5/14)*7/9
=1/2*7/9-5/14*7/9
=7/18-5/18
=2/18
=1/9