Chapter 13 - A Preview of Calculus: The Limit, Derivative, and Integral of a Function - Section 13.2 Algebra Techniques for Finding Limits - 13.2 Assess Your Understanding - Page 902: 3

$c$

We know that $\lim\limits_{x \to a} k(x)=k(a)$, where $a$ as a constant. Thus, in the given statement, we have: $\lim\limits_{x \to c} x=c$ So the answer will be $c$ because $x$ approaches to $c$ in the limit.