分解因式: (1)x3-9x;(2)16x4-1; (3)6xy2-9x2y-y3;(4)(2a-b)2+8ab.

问题描述:

分解因式:
(1)x3-9x;(2)16x4-1;
(3)6xy2-9x2y-y3;(4)(2a-b)2+8ab.

(1)x3-9x,
=x(x2-9),
=x(x+3)(x-3);
(2)16x4-1,
=(4x22-1,
=(4x2+1)(2x+1)(2x-1);
(3)6xy2-9x2y-y3
=-6xy+9x2+y2
=-y(3x-y)2
(4)(2a-b)2+8ab,
=4a2-4ab+b2+8ab,
=4a2+4ab+b2
=(2a+b)2