Have you tried completing the square? Do the numbers have to be integers?
Sorry I didn't read the question carefully. Didn't realise the square on the bottom has to be the square of the numerator.
In this case, I don't think it will be possible to make it into the format you wish, unless 'w' can have 's' in it.
This is because we cannot make the bottom square without introducing more 's' into the denominator, which would have to be part of 'w'.