How do you factor x^3y^2-xy^4?

I found: $x {y}^{2} \left(x - y\right) \left(x + y\right)$
you can collect $x {y}^{2}$ and remember that ${a}^{2} - {b}^{2} = \left(a + b\right) \left(a - b\right)$ to get:
$x {y}^{2} \left({x}^{2} - {y}^{2}\right) = x {y}^{2} \left(x - y\right) \left(x + y\right)$