How do I find the value of this limit? ?

55.20011544... rounded to 5 decimal places is 55.20012, not 55.20011

The answer is as follows:

From the given values, your answer to me seems correct !
Unless there is more to this problem

I'm assuming you can enter different values for x??????????? What others did you try?
Of course if you are only given those two, nobody can guess what the limit is. What I can say for certain is it should not have that many decimals unless the class is a joke.

Maybe you didn't give enough digits.  It's going to be something like the average of the two values.