8/5×7+8/1×5用简便方法计算 6/5×25-6/1×85 简便计算

问题描述:

8/5×7+8/1×5用简便方法计算 6/5×25-6/1×85 简便计算

8/5×7+8/1×5
=8/5×(7+1)
=8/5×8
=5
6/5×25-6/1×85
=6/5×(25-17)
=6/5×8
=3/20