因式分解:(1)4x^n+1-12x^n+9x^n-1;(2)(a^2+3a+2)(4a^2+8a+3)-90;(3)a^4+4

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因式分解:(1)4x^n+1-12x^n+9x^n-1;(2)(a^2+3a+2)(4a^2+8a+3)-90;(3)a^4+4

因式分解:(1)4x^n+1-12x^n+9x^n-1;(2)(a^2+3a+2)(4a^2+8a+3)-90;(3)a^4+4
因式分解:(1)4x^n+1-12x^n+9x^n-1;(2)(a^2+3a+2)(4a^2+8a+3)-90;(3)a^4+4

因式分解:(1)4x^n+1-12x^n+9x^n-1;(2)(a^2+3a+2)(4a^2+8a+3)-90;(3)a^4+4
(1)4x^n+1-12x^n+9x^n-1;
=x^(n-1)(4x²-12x+9)
=x^(n-1)(2x-3)²


(2)(a^2+3a+2)(4a^2+8a+3)-90;
=(a+1)(a+2)(2a+1)(2a+3)-90
=(a+1)(2a+3)(a+2)(2a+1)-90
=(2a²+5a+3)(2a²+5a+2)-90
=(2a²+5a)²+5(2a²+5a)+6-90
=(2a²+5a+12)(2a²+5a-7)
=(2a²+5a+12)(2a+7)(a-1)


(3)a^4+4
=a^4+4a²+4-4a²
=(a²+2)²-4a²
=(a²+2a+2)(a²-2a+2)

(1)4x^n+1-12x^n+9x^n-1;
=x^n-1(4x²-12x+9)
=x^n-1 (2x-3)²
(2)(a^2+3a+2)(4a^2+8a+3)-90
题目有问题
(3)a^4+4
=a^4+4 +4a²-4a²
=(a²+2)²-(2a)²
=(a²+2a+2)(a²-2a+2)