Answer
$x(x-1)(x^2+x+1)$
Work Step by Step
Factoring the $GCF=x$, then the given expression, $
x^4-x
$, is equivalent to
\begin{array}{l}
x(x^3-1)
.\end{array}
Using $a^3-b^3=(a-b)(a^2+ab+b^2)$ or the factoring of the difference of 2 cubes, then,
\begin{array}{l}\require{cancel}
x(x^3-1)
\\\\=
x(x-1)(x^2+x+1)
.\end{array}
