题目

34.5*76.5-345*6.42-123*1.45用简便方法怎算

提问时间：2020-07-17

答案

34.5*76.5-345*6.42-123*1.45
=34.5*76.5-64.2*34.5-12.3*14.5
=34.5*(76.5-64.2)-12.3*14.5
=34.5*12.3-12.3*14.5
=12.3*（34.5-14.5）
=12.3*20
=246