You can
put this solution on YOUR website!54x^9 * y^11 does not simplify any further.
if it was 54y^9 * y^11 it could be simplified.
if it was 54x^9 * x^11 it could be simplified.
as it stand though, 54x^9 * y^11 is simplified as far as it can go as far as I can tell.