因式分解 (1)6mn2-4m3n (2)4a2-16 (3)a4-2a2b2+b4 (4)(x2+9)2-36x2.

问题描述:

因式分解
(1)6mn2-4m3n                       
(2)4a2-16
(3)a4-2a2b2+b4                      
(4)(x2+9)2-36x2

(1)6mn2-4m3n=2mn(3n-2m2);
(2)4a2-16,
=4(a2-4),
=4(a+2)(a-2);
(3)a4-2a2b2+b4
=(a2-b22
=(a+b)2(a-b)2
(4)(x2+9)2-36x2
=(x2+6x+9)(x2-6x+9),
=(x+3)2(x-3)2