问题
解答题
因式分解
(1)3x3-12xy2
(2)(x-1)(x-3)-8.
答案
(1)3x3-12xy2
=3x(x2-4y2)
=3x(x+2y)(x-2y);
(3(x-1)(x-3)-8
=x2-4x+3-8
=x2-4x-5
=(x+1)(x-5).
因式分解
(1)3x3-12xy2
(2)(x-1)(x-3)-8.
(1)3x3-12xy2
=3x(x2-4y2)
=3x(x+2y)(x-2y);
(3(x-1)(x-3)-8
=x2-4x+3-8
=x2-4x-5
=(x+1)(x-5).