You can
put this solution on YOUR website!
I did this thus far but I know it is incorrect.
(n+4)(n-5) n(n+5)
--------- * ------
2n^2 (n-5)(n-5)
This just doesn't look right.
You are certainly on the right track so I won't finish it off. Your error is that n^2-25 factorises as (n-5)(n+5). Fix that and you should be able to complete the rest without difficulties.