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