因式分解 (1)4-12(x-y)+9(x-y)2; (2)2a(x2+1)2-8ax2.

问题描述:

因式分解
(1)4-12(x-y)+9(x-y)2
(2)2a(x2+1)2-8ax2

(1)4-12(x-y)+9(x-y)2
=22-2×2×3(x-y)+[3(x-y)]2
=[2-3(x-y)]2
=(2-3x+3y)2
(2)2a(x2+1)2-8ax2
=2a[(x2+1)2-4x2],
=2a(x2+1-2x)(x2+1+2x),
=2a(x-1)2(x+1)2