34.5*76.5-345*6.42-123*1.45用简便方法怎算_数学解答

34.5*76.5-345*6.42-123*1.45用简便方法怎算

人气：391 ℃　时间：2019-12-25 00:43:38

解答

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