Tomamos como el límite
$$\lim_{x \to 4^+}\left(\frac{4 x + \left(x^{2} - 12\right)}{x^{2} - 2}\right)$$
cambiamos
$$\lim_{x \to 4^+}\left(\frac{4 x + \left(x^{2} - 12\right)}{x^{2} - 2}\right)$$
=
$$\lim_{x \to 4^+}\left(\frac{\left(x - 2\right) \left(x + 6\right)}{x^{2} - 2}\right)$$
=
$$\lim_{x \to 4^+}\left(\frac{\left(x - 2\right) \left(x + 6\right)}{x^{2} - 2}\right) = $$
$$\frac{\left(-2 + 4\right) \left(4 + 6\right)}{-2 + 4^{2}} = $$
= 10/7
Entonces la respuesta definitiva es:
$$\lim_{x \to 4^+}\left(\frac{4 x + \left(x^{2} - 12\right)}{x^{2} - 2}\right) = \frac{10}{7}$$