1.2×22.5+0.08×22.5=22.5×(1.2+0.08)=22.5×1.28=(9×2.5)×(0.4×3.2)=(9×3.2)×(2.5×0.4)=28.8×1=28.8
=22.5*(1.2+0.08)=22.5*1.28=22.5*(1+0.28)=22.5+6.3=28.8