5分之9乘(11.08减15.6除以7.5)
=9/5*(11.08-15.6/7.5)
=9/5*[11.08-(78/5)/(15/2)]
=9/5*[11.08-(78/5)*2/15]
=9/5*[277/25-156/75]
=9/5*675/75
=9/5*675/75
=9/5*27/3
=81/5