12.5×67+53×3.1+72×3.1 与125*1.2*1.5*1.8*35怎样计算简便?
问题描述:
12.5×67+53×3.1+72×3.1 与125*1.2*1.5*1.8*35怎样计算简便?
答
12.5×67+53×3.1+72×3.1=12.5×67+(53+72)×3.1=12.5×67+125×3.1=12.5×67+12.5×31=12.5×(67+31)=12.5×98=12.5×(100-2)=1250-25=1225125×1.2×1.5×1.8×35=(125×1.2)×(1.5×1.8)×35=150×2.7×35=405...