Answer
$(-\infty,-2]U[0,2]$
Work Step by Step
Step 1. Factor the left side to get $x(2+x)(2-x)\ge0$, then identify the boundary points at $x=-2, 0,2$
Step 2. Plot the above points on a number line and obtain four intervals $(-\infty,-2],[-2,0],[0,2],[2,\infty)$
Step 3. Choose test values at $x=-3,-1,1,3$ for each interval and test the inequality. The results are $T, F,T,F$ (T for True, F for False) for each interval.
Step 4. The solutions are the intervals with true results: $(-\infty,-2]U[0,2]$