1.25*5.6+2.25*4.4 =1.25*5.6+（1+1.25）*4.4 =1.25*5.6+1.25*4.4+4.4 =1.25*（5.6+4.4）+4.4 =1.25*10+4.4 =12.5+4.4 =16.9