4.7×2.8+2.5×2.8+7.2×7.2(用简便方法计算)
问题描述:
4.7×2.8+2.5×2.8+7.2×7.2(用简便方法计算)
答
4.7×2.8+2.5×2.8+7.2×7.2
=(4.7+2.5)×2.8+7.2×7.2
=7.2×2.8+7.2×7.2
=7.2×(2.8+7.2)
=72