问题
计算题
把下列各式分解因式:
(1)3a(x﹣y)﹣5b(y﹣x)
(2)a4﹣1
(3)﹣b3+4ab2﹣4a2b.
答案
解:(1)3a(x﹣y)﹣5b(y﹣x),
=3a(x﹣y)+5b(x﹣y),
=(x﹣y)(3a+5b);
(2)a4﹣1,=(a2﹣1)(a2+1),
=(a﹣1)(a+1)(a2+1);
(3)﹣b3+4ab2﹣4a2b,
=﹣b(b2﹣4ab+4a2),
=﹣b(b﹣2a)2.