When you reply, please include a clarification of what the actual expression is. What you've posted means the following:
. . . . .\(\displaystyle \large{x^2\,+\,4x\,-\,\frac{5}{x^2}}\)
But I have a suspicion that you might mean this instead:
. . . . .\(\displaystyle \large{\frac{x^2\,+\,4x\,-\,5}{x^2}}\)
Naturally, the final answer will vary depending upon which, if either, you mean.
Thank you.
Eliz.