58.6*58.6-41.4*41.4的简便算法
问题描述:
58.6*58.6-41.4*41.4的简便算法
答
运用a² -b² =(a+b )(a-b)
=(58.6+41.4)*(58.6-41.4)
=100*17.2
=1720
答:是1720