Answer
$4$
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.
$\lim_\limits{x\to 3} \dfrac{4x-12}{x-3}=\dfrac{\lim_\limits{x\to 3}
4 (x-3)}{\lim_\limits{x\to 3} x-3}=\lim_\limits{x\to 3} 4=4$
