因式分解(1)(a+1)(a+4)-4(a-1)^2 (2)(x+2y)(x-2y)(x^2+4y^2)

因式分解(1)(a+1)(a+4)-4(a-1)^2 (2)(x+2y)(x-2y)(x^2+4y^2)
因式分解(1)(a+1)(a+4)-4(a-1)^2 (2)(x+2y)(x-2y)(x^2+4y^2)

因式分解(1)(a+1)(a+4)-4(a-1)^2 (2)(x+2y)(x-2y)(x^2+4y^2)
原式=a²+5a+4-4a²+8a-4
=-3a²+13a
原式=(x²-4xy)(x²+4y²)
=x^4-16y^4

(1)
(a+1)(a+4)-4(a-1)²
=a²+5a+4-4a²+8a-4
=-3a²+13a
=-a(3a-13)
(2)
(x+2y)(x-2y)(x²+4y²)
=(x²-4y²)(x²+4y²)
=x⁴-16y⁴ 第二题不是因式分解，是化简题。

(1)(a+1)(a+4)-4(a-1)^2
=a²+5a+4-4(a²-2a+1)
=-3a²+13a

=-a(3a-13)


(2)(x+2y)(x-2y)(x^2+4y^2)
=(x²-4y²)(x²+4y²)
=x的4次方-16y的4次方

(1)(a+1)(a+4)-4(a-1)^2
=a^2+5a+4-4a^2+8a-4
=-3a^2+13a
=-a(3a-13)
(2)(x+2y)(x-2y)(x^2+4y^2)
=(x^2-4y^2)(x^2+4y^2)
=x^4-16y^4