Answer
$2(x^2+9)(x+3)(x-3)$
Work Step by Step
Factor out the GCF of $2$ to obtain:
$=2(x^4-81)$
The binomial above can be written as $(x^2)^2-9^2$, so the expression above is equivalent to:
$=2[(x^2)^2-9^2]$
Factor the difference of two squares using the formula $a^2-b^2=(a+b)(a-b)$ to obtain:
$=2(x^2+9)(x^2-9)
\\=2(x^2+9)(x^2-3^2)$
Factor the difference of two squares using the same formula to obtain:
$=2(x^2+9)(x+3)(x-3)$
