102.31×59 57.5-14.25-15 简便运算

问题描述:

102.31×59 57.5-14.25-15 简便运算

102.31×59=(102+0.31)×(60-1)=102×60-102+0.31×60-0.31=6120-102+18.6-0.31=6036.2957.5-14.25-15=57.5-(14.25+15)=57.5-29.25=57.5-30+0.75=28.25