Question

The function f(x) = 2.50x + 11.50 relates how much Kate pays for data service, f(x), to the number of songs, x, she downloads in a month. What is the value and meaning of f(14)?

Answer 1

The function f(x) shows how much Kate pays for the data service for downloading x songs in a month. So f(14) will represent the amount that Kate will have to pay for downloading 14 songs in a month.

f(x) = 2.50x + 11.50

Replacing x by 14, we get:

f(14) = 2.50(14) + 11.50 = 46.5

Thus, Kate will have to pay $ 46.5 for downloading 14 songs in a month 

Answer 2

To solve this problem you must apply the proccedure shown below:
 1. You have the function f(x) = 2.50x + 11.50 where f(x) relates how much Kate pays for data service and x is the number of songs.

 2. Therefore, when x=14 then f(14):

  f(x) = 2.50x + 11.50 
  f(14) = 2.50(14) + 11.50
  f(14)=46.5

 The answer is: The value is 46.5, which is the amount that  Kate pays for data service for download 14 songs in a month.