Answer
$2$
Work Step by Step
Recall that if $ f $ is a polynomial function, then we have $\lim_\limits{x\to a}f(x)=f(a)$.
In order to to find the limit, we will plug $ a $ into the function and then simplify.
$\lim_\limits{x\to 1} \dfrac{x^2-1}{x-1}=\dfrac{\lim_\limits{x\to 1}
(x-1)(x+1)}{\lim_\limits{x\to 1} x-1}=\lim_\limits{x\to 1} x+1=2$
