Answer
$[1,2]U(3,\infty)$. See graph.
Work Step by Step
Step 1. Identify boundary points $x=1,2,3$ and intervals $(-\infty,1],[1,2],[2,3),(3,\infty)$
Step 2. Choose test values $x=0,1.5,2.5,4$ for each interval and evaluate the inequality to get $False,\ True,\ False,\ True$
Step 3. Thus we have the solution interval(s) $[1,2]U(3,\infty)$. See graph.