Final answer:
To find the limit of the given expression, factor the numerator and simplify. Substituting the value of x into the expression gives the final limit.
Step-by-step explanation:
To find the limit of the given expression, we can simplify it by factoring the numerator as the difference of squares. x² - 81 can be written as (x + 9)(x - 9). Now, cancel out the common factor of (x - 9) in the numerator and denominator. The limit becomes lim as x approaches 9 of (x + 9).
Substituting x = 9 into the expression, we get 9 + 9 = 18. Therefore, the limit of the given expression as x approaches 9 is 18.