因式分解：x³+2x²-6x-9

Question

需要详细解答

Answer 1

追问

谢谢你的答案，方法很好，不过只能采纳一个，😂，sorry.

Answer 2

x³+2x²-6x-9
=x³+3x²-x²-6x-9
=x²(x+3)-(x+3)²
=(x+3)(x²-x-3)本回答被提问者和网友采纳

Answer 3

x³+2x²-6x-9=x³+x²-6x+x²-9=x(x²+x-6)+(x-3)(x+3)=x(x-2)(x+3)+(x-3)(x+3)
=(x+3)(x²-2x+x-3)=(x+3)(x²-x-3)