Question 65035
{{{x^2-2xy+y^2-4}}}
{{{(x^2-2xy+y^2)-4}}}
{{{(x-y)^2-4}}}
{{{(x-y)^2-2^2}}}
ie A difference of squares
{{{((x-y)-2)((x-y)+2)}}}
{{{(x-y-2)(x-y+2)}}}