简便计算 (1)36×64+36² (2)(5×1/2)²-(4×1/2)²
问题描述:
简便计算 (1)36×64+36² (2)(5×1/2)²-(4×1/2)²
答
(1)36×64+36²
=36×(64+36)
=36×100
=3600
(2)(5×1/2)²-(4×1/2)²
=(5/2+4/2)×(5/2-4/2)【平方差公式】
=(9/2)×(1/2)
=9/4