Tomamos como el límite
$$\lim_{x \to 3^+}\left(\frac{- 4 x^{2} + \left(x^{3} - 1\right)}{x^{2} - 5}\right)$$
cambiamos
$$\lim_{x \to 3^+}\left(\frac{- 4 x^{2} + \left(x^{3} - 1\right)}{x^{2} - 5}\right)$$
=
$$\lim_{x \to 3^+}\left(\frac{x^{3} - 4 x^{2} - 1}{x^{2} - 5}\right)$$
=
$$\lim_{x \to 3^+}\left(\frac{x^{3} - 4 x^{2} - 1}{x^{2} - 5}\right) = $$
$$\frac{- 4 \cdot 3^{2} - 1 + 3^{3}}{-5 + 3^{2}} = $$
= -5/2
Entonces la respuesta definitiva es:
$$\lim_{x \to 3^+}\left(\frac{- 4 x^{2} + \left(x^{3} - 1\right)}{x^{2} - 5}\right) = - \frac{5}{2}$$