来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/11/19 02:03:54
因式分解:(x+3)(x²-1)(x+5)-9
答:
(x+3)(x²-1)(x+5)-9
=(x-1)(x+1)(x+3)(x+5)-9
=[(x-1)(x+5)]*[(x+1)(x+3)]-9
=(x^2+4x-5)(x^2+4x+3)-9
=(x^2+4x)^2 -2(x^2+4x)-15-9
=(x^2+4x)^2 -2(x^2+4x) -6*4
=(x^2+4x-6)(x^2+4x+4)
=(x^2+4x-6)(x+2)^2