Answer
$(-\infty,-4]U[0,4]$
Work Step by Step
Step 1. Factor the left side to get $x(4+x)(4-x)\ge0$, then identify the boundary points at $x=-4, 0,4$
Step 2. Plot the above points on a number line and obtain four intervals $(-\infty,-4],[-4,0],[0,4],[4,\infty)$
Step 3. Choose test values at $x=-5,-1,1,5$ 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: $(-\infty,-4]U[0,4]$
