如图
提取公因数 逆用乘方分配律
4.2/1.5-1.5*0.6 =14/5-0.9 =2.8-0.9 =1.9 51.6/[(3又2/5-1.25)*4/5] =51.6/[(3.4-1.25)*0.8] =51.6/[2.72-1] =51.6/1.72 =30
