（80.75÷8.5＋7.75）×3.2
=[(85-4.25)÷8.5+(8-0.25)]×4×0.8
=[10-0.5+(8-0.25)]×4×0.8
=(40-2+32-1)×0.8
=(70-1)×0.8
=56-0.8
=55.2简便一些步骤多就是为了使运算方法简单。能不能不加大括号可以啊（80.75÷8.5＋7.75）×3.2=(85÷8.5-4.25÷8.5+8-0.25)×4×0.8=(10-0.5+8-0.25)×4×0.8=(40-2+32-1)×0.8=(70-1)×0.8=56-0.8=55.2