Answer:
(x + 1)(x - 1)(x + 4)
Step-by-step explanation:
Group the polynomial:
([tex]x^{3} + 4x^{2}[/tex])(-x - 4)
Take out the GCF (Greatest Common Factor) for both:
[tex]x^2[/tex] (x + 4) -1 (x + 4)
Put it together:
([tex]x^2\\[/tex] - 1) (x + 4)
But, ( [tex]x^2[/tex] - 1 ) can still be factored, by splitting it into 2:
(x + 1) (x - 1)
Now put it all together:
(x + 1)(x - 1)(x + 4)
