｛5/2-（3/8+1/6-3/4）×24｝/5×(-1)
=[5/2-(3/8)*24+(1/6)*24-(3/4)*24]/5*(-1)
=(5/2-9+4-18)/5*(-1)
=(5/2-23)/5*(-1)
=(1/2-23/5)*(-1)
=(0.5-4.6)*(-1)
=4.1