[(1又3分之2x2+2.5)/8分之7-2又5分之1]/1.6=?
={(10/3+5/2)/7/8-11/5}/8/5
={(35/6*8/7)-11/5}*5/8
=(20/3-11/5)*5/8
=67/15*5/8
=67/24
=2又24分19