[答案]
(1)(x2+2y2+2xy)(x2+2y2﹣2xy);(2)(x+b)(x﹣2a﹣b);(3)(x+1)(x﹣2)(x+3).
[解析]
解:(1)x4+4y4=x4+4x2y2+4y4﹣4x2y2
=(x2+2y2)2﹣(2xy)2
=(x2+2y2+2xy)(x2+2y2﹣2xy);
(2)原式=x2﹣2ax+a2﹣a2﹣b2﹣2ab
=(x﹣a)2﹣(a+b)2
=(x﹣a+a+b)(x﹣a﹣a﹣b)
=(x+b)(x﹣2a﹣b);
(3)原式=x3+2x2+x﹣6x﹣6
=x(x2+2x+1)﹣6(x+1)
=x(x+1)2﹣6(x+1)
=(x+1)[x(x+1)﹣6]
=(x+1)(x2+x﹣6)
=(x+1)(x﹣2)(x+3).
[点评]
本题考查了"幂的乘方与积的乘方,",属于"基础题",熟悉题型是解题的关键。