0.8×0.12÷0.08
=10*0.12
=1.2
4.9÷（0.7÷0.4）
=4.9/(7/4)
=4.9*4/7
=2.8
1.5÷5.5×0.55
=1.5*0.55/5.5
=1.5*0.1
=0.15
2.5×（4.6÷0.25）
=2.5*4.6/0.25
=10*4.6
=46