Answer
$\left( -\infty,-10 \right]\cup[10,\infty)$
Work Step by Step
Since for any $a\gt0$, $|x|\ge a$ implies $x\ge a$ OR $x\le -a$, then the given inequality, $
|x|\ge10
,$ is equivalent to
\begin{array}{l}\require{cancel}
x\ge10
,\\\\\text{OR}\\\\
x\le-10
.\end{array}
Hence, the solution set is $
\left( -\infty,-10 \right]\cup[10,\infty)
.$
See graph below.