九分之四除以中括号五分之四减小括号三分之一加五分之一怎么简便？

Question

如题所述

Answer 1

4/9÷[4/5一（1/3十1/5）]
=4/9÷[4/5一1/5一1/3]
=4/9÷[3/5一1/3]
=4/9÷[9/15一5/15]
=4/9÷4/15
=5/3