Question 65365
{{{x-y-x^3+x^2y}}}
Rearrange to get two sets of number with common factors
{{{-x^3+x+x^2y-y}}}
{{{-x(x^2-1)+y(x^2-1)}}}
Take the common factor of (x^2-1) out.
{{{(x^2-1)(-x+y)}}}
{{{(x^2-1)(y-x)}}}