Answer
$x(x^2+1)(x+1)(x-1)$
Work Step by Step
Pull out the greatest common factor. Then use the formula $a^2-b^2=(a+b)(a-b)$. Then use it again to factor the second set of parentheses completely.
$x^5-x$
$x(x^4-1)$
$x(x^2+1)(x^2-1)$
$x(x^2+1)(x+1)(x-1)$
