Break everything into prime factors









So 



becomes



Put parentheses arond every pair of like factors which are multiplied:



Every pair of multiplied like factors is the square of that factor,
so write each pair as a square:



All the squares on top come out in front of the radical without an exponent
as a numerator.  All those on the bottom come out likewise but are in the
denominator in front.  Every factor that did not pair up stays under the
radical:



Now write  for  and  for 
and what's under the radical cancels out and leaves just 



or



or



Edwin