23: You should get

If you decided to get rid of the square root, you should have got

This fraction is obviously of the type "infinity over infinity" (note that thanks to the addition in the denominator, there is no trouble when putting together the root and the x), but experience shows that applying the l'Hospital rule to expressions with roots is seldom wise. Fortunately, this expression can be also fitted to the box "polynomials and ratios with powers". We determined that the inside root behaves like x² when x grows large, so this is the order of the numerator. In the denominator, the large roots term was found to behave like x, which is the same order as the term "+x". Thus the denominator is of the order x. Factoring out and cancelling gives

Obviously, the first solution is a bit simpler.

Answer