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)

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