As seen in veileen's post, there's an abundance of solutions to this inequality.
Therefore, I think that all you can do is simplify this expression a bit by quadrating the whole thing, so that you can get a clearer relationship between n and x.
If you quadrate the whole inequality, I think that this will be the end result:
but I might have been a bit sloppy while I did it, so I can be a little bit off.
Do you mean like something like this:
Where the only natural number for a given n, which makes the inequality true, is x.
I personally don't know how I should go about determining the exact value of x, i.e. x= 'something', when I'm only given this type of inequality, which contains many different solutions.