Please be sure to include the instructions when you post a problem.
For example: "Factor the difference of 2 squares 9xy^2 - 16y."
Unfortunately, your 9xy^2 is not a perfect square. Please double check the original problem. Did you mean 9(xy)^2 - 16? Unfortunately, 16y is not a perfect square either.
If you had 9(xy)^2 - 16y^2, this would factor into (3xy + 4y)(3xy - 4y).
