简算题,分数的

问题描述:

简算题,分数的
5/7-(1/18-1/6)/1/3

5/7-(1/18-1/6)/1/3
=5/7-(1/18-1/6)×3
=5/7-(1/18×3-1/6×3)
=5/7-(1/6-1/2)
=5/7-(-1/3)
=5/7+1/3
=22/21