Haley pays a monthly fee of $20 for her cell phone and then pays 5 cents per minute used. The total cost of Haley’s monthly cell phone bill can be expressed by the function C(m) = 0.05m + 20, where m is the number of minutes used. What are the domain and range of the function C(m)?

The domain is

The range is:

Step-by-step explanation:

Domain and range of a function:

The domain of a function are the values that the input assumes, while the range are the values that the output assumes.

In this question:

m is the input, which is the number of phone calls, which can be any number between 0 and infinite. So

The domain is

When the input is m = 0, the value of C(0) = 20. As m increases, so does C(m). This means that:

The range is:

n=9

step-by-step explanation:

7 times a number = 7n

decreased by 13 = 7n-13

same as is =

5 times the number = 5n

increased by 5 = 5n+5

7n-13 = 5n+5

2n=18

n=9