Step-by-step explanation:
[tex]\displaystyle \lim_{x \to 1} \dfrac{(x^2 - 1)}{(x-1)} = \lim_{x \to 1} \dfrac{(x - 1)(x+1)}{(x-1)} [/tex]
[tex]\:\:\:\:\:\:\:\:\displaystyle = \lim_{x \to 1} (x+1) =2[/tex]