#### Answer

$2y(1-x^3y)(1+x^3y)$

#### Work Step by Step

RECALL:
A difference of two squares can be factored using the formula:
$m^2-n^2=(m-n)(m+n)$
Factor out the greatest common factor, $2y$, to obtain:
$=2y(1-x^6y^2)
\\=2y[1^2-(x^3y)^2]$
The binomial is a difference of two squares.
Factor the given difference of two squares using the formula above with $m=1$ and $n=x^3y$ to obtain:
$=2y(1-x^3y)(1+x^3y)$