If a fraction is a negative should the negative sign be in the numerator denominator both or it doesn't matter

Here's the rule for working with these things:

There are 3 signs associated with a fraction:
=> the sign of the numerator
=> the sign of the denominator
=> the sign of the whole fraction; (if the fraction were in
     parentheses, this sign would be written outside).

-- You can change any 2 of them without changing the value of the fraction.

-- Changing any 1 of them changes the effective sign.


Now, you said the fraction is negative.
So, let's start with the positive fraction, and see the different ways
that we could make it a negative fraction:

=> mark only the numerator negative
=> mark only the denominator negative
=> put parentheses around the fraction, and mark it negative outside

If you do any one of these things to a normal positive fraction,
it turns into a negative fraction.

Look at the choices you listed in the question:

-- in the numerator only ?  Yes.  That makes it a negative fraction.

-- in the denominator only ?  Yes. That makes it a negative fraction.

-- both ?  No.  That makes it the same as a positive fraction. 

-- put parentheses around the fraction, and a negative sign outside ?
   Yes.  This makes it a negative fraction.

-- it doesn't matter ?   No.  I hope you can see that it does matter.

Have I confused you ?
Is this more than you wanted to know ?