# Thread: What's the step after this?

1. ## What's the step after this?

$x^3 - x - y^3 + y$

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

What do I do after this?
$(x - y)(x^2 + xy + y^2 -1 )$

2. Originally Posted by lax600
$x^3 - x - y^3 + y$

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

What do I do after this?
$(x - y)(x^2 + xy + y^2 -1 )$
$= (x^3 - y^3) - (x - y)$
$= (x - y)(x^2 + xy + y^2) - (x - y)$