I need this to be in this format :
I can easily factor the top to get the "s+a",
but how can I factor the bottom in such a way to get the required form? Can someone help please?
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'.