Awelder earns $20 an hour for the first 40 hours she works in a week and $30 for every hour over 40 hours. determine a piece wise function f(x) that can be used to determine the welder's earnings when she works for x hours in a week

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 every hour over 40 hours. The number of hours over 40 hours is x-40. 

32

step-by-step explanation:

these are your clues: 1. kim ran 18 races2. this was four fewer races than twice thenumber, notice it says twice the number, so you would do the equation 18x2-4; which equals the number 32.thus, 32 is your answer.