If she works 40 hours or less then she earns 20x dollars.
If she works more than 40 hours, then she earns 20×40 dollars for the first 40 hours and 30×(x-40) dollars for <span>every hour over 40 hours. The number of hours over 40 hours is x-40.</span>
If she works more than 40 hours, then she earns 20×40 dollars for the first 40 hours and 30×(x-40) dollars for <span>every hour over 40 hours. The number of hours over 40 hours is x-40.</span>