how do i simplify 3m+n/4n^2m + 3m +n +5/4n^2m

If your problem is this:

(3m + n)/(4n^2m) + (3m + n + 5)/(4n^2m)

Then we have:

3m + n + 3m + n + 5
-------------------
4n^2m

Combine like terms:

6m + 2n + 5
-----------
4n^2m

I hope this helps and is what you were asking.