1. The problem statement, all variables and given/known data: The question asks to find the limit as x approaches 8 of (2x^2 - 3x + 4). So I use the limit law/property which states that if f is a polynomial or rational function and if a is in the domain of f, then the limit of f(x) as x approaches a is f(a). Correct? 2. Relevant equations: Now, since the limit law I described clearly fits as this is a polynomial expression, and x can be any real number, I plug in 8, aka f(a) = f(8). The answer I get does not agree with the answer key. 3. The attempt at a solution: Calculus never came easy for me, but here is my attempt: lim x->8 (2x^2 - 3x + 4) = 2(8)^2 - 3(8) + 4 = 108 Do I even have the right approach?? Here's the answer key: lim x->8 (2x^2 - 3x + 4) = 2(5)^2 - 3(5) + 4 = 39 Assuming no error in the actual substitutions & calculation, where the heck did the key get 5??? Am I missing something here, or is the answer key throwing out a red herring? 99.99% of the time, whenever the answer key disagrees with my answer: I did something wrong. What happened this time? It seems like that instead of using 8, they used 5... why?