1、 75.6-35.6/0.89
=75.6-40
=35.6
2、2.5*3.1*1.2
=2.5*1.2*3.1
=9.3
3、（80.75/8.5+7.75）*3.2
=(9.5+7.75)*3.2
=17.25*4*0.8
=69*0.8
=55.2
4、25.8+3.76*0.5
=25.8+1.88
=27.68
5、10.8+32*2.5-10.8
=32*2.5
=8*4*2.5
=8*10
=80