7.6*[63.9/(7-2.5)] 简便计算如何算?

分类: 作业答案 • 2021-12-19 15:54:00

问题描述：

答

7.6*[63.9/(7-2.5)]
=7.6*63.9/4.5
=7.6*7.1*9/(0.5*9)
=7.6*7.1*2
=7.6*(7+0.1)*2
=(7.6*7+7.6*0.1)*2
=(53.2+0.76)*2
=53.96*2
=107.92

答

用计算器比较简便
要是手算的话63.9/(7-2.5)分子分母约掉一个9得7.1*2
然后7.6*7.1*2= 53.96*2= 107.92

答

5.6÷3.5+4.7
=8/5+4.7
=1.6+4.7
=6.3