For this case we must factor the following expression:
[tex]4x ^ 3 + x ^ 2-8x-2[/tex]
We group the first two and the last two terms:
[tex](4x ^ 3 + x ^ 2) + (- 8x-2)[/tex]
We factor the highest common denominator of each group:
[tex]x ^ 2 (4x + 1) -2 (4x + 1)[/tex]
We take the common factor[tex]4x + 1:[/tex]
[tex](4x + 1) (x ^ 2-2)[/tex]
Answer:
[tex](4x + 1) (x ^ 2-2)[/tex]