[3-(1又4分之1+0.75）除以1又8分之3]乘5又7分之1
=[3-(5/4+3/4)]÷11/8]×36/7
=[3-(8/4)×8/11]×36/7
=[3-2×8/11]×36/7
=[3-16/11]×36/7
=17/11×36/7
=7又77分之73