29.94-(19.94+12.8)+2.8用简便计算
问题描述:
29.94-(19.94+12.8)+2.8用简便计算
尽快
答
29.94-(19.94+12.8)+2.8
=29.94-19.94-12.8+2.8
=(29.94-19.94)-(12.8-2.8)
=0