脱式计算,能简算的要简算(要列式)12*5/117.6*2又1/4+7又3/5*7又3/4(0.75÷3-0.2)*(1-4/5)解方程60%x-35%x=25
问题描述:
脱式计算,能简算的要简算(要列式)
12*5/11
7.6*2又1/4+7又3/5*7又3/4
(0.75÷3-0.2)*(1-4/5)
解方程
60%x-35%x=25
答
12×5/11 = 60/11 7.6×(2×1/4)+ 7×3/5 -7×3/4= 7.6/2 + 7×(3/5-3/4)= 3.8 + 7×(-3/20)= 19/5 - 21/20=(19×4 -21 )/20= 55/20= 11/4 =2又3/4(0.75÷3-0.2)×(1-4/5)= (0.25-0.2)× (1/5) 注:...