If all you want is just how this is written, then the answer is
[tex] \dfrac{4}{x} - 1 [/tex]
That's the way it reads. However you may have meant
[tex] \dfrac{x}{4} - 1 [/tex]
We cannot exactly tell from the wording what is meant. I would choose the first one, if this multiple choice. I would note the ambiguity if a person is doing the marking.