Question

For which function does f (14) = 23?

A. f(x) = 1/2x - 20

B. f(x) = 3x - 7

C. f(x) = x +9

D. f(x) = 14x + 23

Answer 1

C.
`f(x) = x + 9`

Explanation:

To find the answer we need to put 14 into each of the functions. When it says
`f(14)` we are basically replacing every value in the function with 14.

So for the first function we can say.

A.
`f(14) = (1)/(2(14)) - 20` =
`-(559)/(28)`

This doesn't equal 23 so we can go to the next function and put in 14.

B.
`3(14) - 7 = 35`

C.
`14 + 9 = 23`

For C we get
`f(14) = 23` which is what we are looking for so the function is
`f(x) = x + 9`.