=13.7×(1-0.5)
=13.7×0.5
=6.85
13.7-13.7×0.5=13.7×1-13.7×0.5=13.7×(1-0.5)=13.7×0.5=6.85
13.7-13.7x0.5=13.7x(1-0.5)=13.7x0.5=6.85求采纳
=13.7*(1-0.5)=13.7*0.5=6.85