Answer:
4
Step-by-step explanation:
Answer:
The second option
Step-by-step explanation:
The second option because it is the one in which if you multiply f4 to the values of x, you would get y.
And that is why it is the second option.
IDK IDK IDK IDK I DONT KNOW
Given that,

To find,
The domain of f(x).
Solution,
We have, 
To find domain,
The term under the square root must be positive or null as follows :

Adding 3 both sides

So, the domain is x-3>0
.
C= 20-0.75x
c= 20-0.75(9)
c= 20-6.75
c= 13.25
Here c is the amount of change and x is the number of books bought.
The customer's change will be $13.25