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

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Answer 1 · 2017-01-02T13:14:47

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.

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:

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

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