分解因式：(x+3)(x+5)+x²-9

分类: 作业答案 • 2022-05-02 11:55:18

问题描述：

答

(x+3)(x+5)+x²-9
=(x+3)(x+5)+(x+3)(x-3)
=(x+3)[(x+5)+(x-3)]
=(x+3)(2x+2)
=2(x+3)(x+1)