简便计算:3.25x(7.4一0.86)
问题描述：
简便计算:3.25x(7.4一0.86)
答
3.25x(7.4一0.86)
=6.5*(7.4一0.86)/2=6.5*(3.7-0.43)=6.5*3.27=21.255