How do you solve and inequality on a number line?

To solve an inequality on a number line, first isolate the variable on one side of the inequality. Then, determine the critical points by setting the inequality to equal zero and solving for the variable. Next, plot these points on the number line, and use test intervals to determine where the inequality holds true. Finally, shade the appropriate region of the number line and use open or closed circles to indicate whether the endpoints are included or not, based on whether the inequality is strict (>, <) or inclusive (≥, ≤).