因式分解: (1)25a-5a2; (2)(x-y)2+4xy.

问题描述:

因式分解:
(1)25a-5a2
(2)(x-y)2+4xy.

(1)25a-5a2=5a(5-a);
(2)(x-y)2+4xy,
=x2+2xy+y2
=(x+y)2