｛15/29 - (0.25+1/3）*7.2｝/14/5
问题描述：
｛15/29 - (0.25+1/3）*7.2｝/14/5
答
｛29/15 - (0.25+1/3）*7.2｝/14/5
=[29/15-(1/4+1/3)*36/5]*5/14
=(29/15-7/12*36/5)*5/14
=(29/15-21/5)*5/14
=29/15*5/14-21/5*5/14
=29/42-3/2
=-34/42
=-17/21