Question

If `f(x)=3(x+5)+4/x`, what is f(a+2)?

Answer 1

To determine `f(a+2)` you need to substitute `color(red)(a + 2)` for each occurrence of `x` in the given function. See below for full explanation.

Explanation:

If

`f(color(red)(x)) = 3(color(red)(x) + 5) + 4/color(red)(x)`

Then

`f(color(red)(a + 2)) = 3(color(red)(a + 2) + 5) + 4/color(red)(a + 2)`

Simplifying gives:

`f(color(red)(a + 2)) = 3(a + 7) + 4/(a + 2)`