please answer quick and have an explanation lol

Answer:
0 <= x <= 18 , -3.33
Step-by-step explanation:
1) in order to get the domain, you must focus on the X axis. So the X axis the maximum number is 18 and the minimum number is 0. Finally the domain is from 0 to 18.
2) In order to get the average rate you will need to find the slope of the graph. in this case to find the slope you have to divide 60/18 and that will give you 3.33 but the slope is more than 90 degrees so for that reason the slope is negativo. Finally the slope is -3.33