Answer
$(x^3+2)(x^3-14)$.
Work Step by Step
The given expression is
$=x^6-12x^3-28$
Rewrite the middle term $-12x^3$ as $-14x^3+2x^3$.
$=x^6-14x^3+2x^3-28$
Group the terms.
$=(x^6-14x^3)+(2x^3-28)$
Factor from each term.
$=x^3(x^3-14)+2(x^3-14)$
Factor out $(x^3-14)$.
$=(x^3-14)(x^3+2)$
Rearrange.
$=(x^3+2)(x^3-14)$.
