因式分解:(a^2+7a+12)(a^2-5a+6)-112
来源:学生作业帮 编辑:大师作文网作业帮 分类:数学作业 时间:2024/11/12 07:01:49
因式分解:(a^2+7a+12)(a^2-5a+6)-112
=(a+3)(a+4)(a-2)(a-3)-112
=【(a+3)(a-2)】【(a+4)(a-3)】-112
=(a²+a-6)(a²+a-12)-112
=(a²+a)²-18(a²+a)+72-112
=(a²+a)²-18(a²+a)-40
=(a²+a)²-18(a²+a)+81-121
=(a²+a-9)²-11²
=(a²+a-9+11)(a²+a-9-11)
=(a²+a+2)(a²+a-20)
=(a²+a+2)(a+5)(a-4)
=【(a+3)(a-2)】【(a+4)(a-3)】-112
=(a²+a-6)(a²+a-12)-112
=(a²+a)²-18(a²+a)+72-112
=(a²+a)²-18(a²+a)-40
=(a²+a)²-18(a²+a)+81-121
=(a²+a-9)²-11²
=(a²+a-9+11)(a²+a-9-11)
=(a²+a+2)(a²+a-20)
=(a²+a+2)(a+5)(a-4)