Question

3.5*1.3-37.5/25怎样做简便

Answer 1

先做37.5/25 = (37.5*4)/(25*4) = 150/100 = 1.5,由于这个结果是1.5,所以可以拆解前面的数,原式 = (2+1.5)*1.3 - 1.5 = 2*1.3 + 1.5*(1.3-1) = 2.6 + 1.5*0.3 = 2.6 + 0.45 = 3.05