Answer
$(-\infty,-1)U(-1,3)$
Work Step by Step
Step 1. Identify the boundary point at $x=-1,3$
Step 2. Plot the above points on a number line and obtain three intervals $(-\infty,-1),(-1,3),(3,\infty)$
Step 3. Choose test values at $x=-2,0,4$ for each interval and test the inequality. The results are $T,T, F$ (T for True, F for False) for each interval.
Step 4. The solutions are the intervals with true results: $(-\infty,-1)U(-1,3)$