Answer:
A
Step-by-step explanation:
So we have the two functions:

And we want to find (f/g)(x).
This is the same as:

So, substitute (2x+5) for f(x) and (x-8) for g(x). So:

Now, we want to find the domain.
Note that this is a rational function. The domain of a rational function is always all real numbers <em>except</em> when the denominator equals 0. This is because, remember, you can't divide by 0!
So, to find the domain restrictions, set the denominator equal to 0 and solve for x. So:

Solve for x. Add 8 to both sides:

So, our domain is all real numbers except for 8. We can check this, when x is 8, our function is 21/0, which is undefined.
Therefore, our answer is A.
And we're done!
Edit: Typo