the answer is
[tex]24 {x}^{7} {y}^{4} \sqrt{7y} [/tex]
because you find what times what equal 63 (3*21) and then b/c 3 is prime you leave it alone and you only factor out 21 (7*3) because it's a square root you have to find a pair of prime numbers (3 and 3) so you multiply that by the 8 (24 - it stays outside the radical) and then you move on to the x and y. So for the x and y you just look at the exponent and figure out how many pairs of 2 you can make (x^14 turns into x^7 and y^9 turns into y^4 and the extra y stays inside the radical w/ the 7)
