Answer:
Total hours of volunteer work
Explanation:
Question 19
Since the equation needs to represent the number of hours Rebecca still has to work and that number will Decrease by 3 each day, it should start with 15 and then Subtract 3 times the number of days: y=15 -3x or y= -3x+15.
Question 20
Before Rebecca completes ANY volunteer work hours (days worked equals zero), she has 15 still to do.