。4.5✖️9✖️1.2=4.5*(10-1)*1.2=4.5*10*1.2-4.5*1*1.2=45*1.2-4.5*1.2=4.5*10*1.2-4.5*1.2=4.5*(10*1.2-1.2)=4.5*(12-1.2)=4.5*10.8=4.5*(10+0.8)=4.5*10+4.5*0.8=45+3.6=48.6
4.5✖️9✖️1.2=48.6
