(y+2)²-(2-y)²等于多少,
问题描述:
(y+2)²-(2-y)²等于多少,
答
=(y+2+2-y)(y+2-2+y)
=4×2y
=8y
(y+2)²-(2-y)²等于多少,
=(y+2+2-y)(y+2-2+y)
=4×2y
=8y