0.28×9+0.28 6.6-0.78+2.4-3.22

问题描述:

0.28×9+0.28 6.6-0.78+2.4-3.22

0.28×9+0.28
=0.28×(9+1)
=0.28×10
=2.8
6.6-0.78+2.4-3.22
=(6.6+2.4)-(0.78+3.22)
=9-4
=5