用简便方法计算:6/13*39+7/13*40
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/17 20:19:48
用简便方法计算:6/13*39+7/13*40
用简便方法计算:6/13*39+7/13*40
用简便方法计算:6/13*39+7/13*40
6/13*39+7/13*40
=6/13*39+7/13*(39+1)
=6/13*39+7/13*39+7/13
=(6/13+7/13)*39+7/13
=1*39+7/13
=39又7/13