Tomamos como el límite
$$\lim_{x \to \frac{1}{2}^+}\left(\frac{2 x - 1}{x^{2} + \left(x + 1\right)}\right)$$
cambiamos
$$\lim_{x \to \frac{1}{2}^+}\left(\frac{2 x - 1}{x^{2} + \left(x + 1\right)}\right)$$
=
$$\lim_{x \to \frac{1}{2}^+}\left(\frac{2 x - 1}{x^{2} + x + 1}\right)$$
=
$$\lim_{x \to \frac{1}{2}^+}\left(\frac{2 x - 1}{x^{2} + x + 1}\right) = $$
$$\frac{-1 + \frac{2}{2}}{\left(\frac{1}{2}\right)^{2} + \frac{1}{2} + 1} = $$
= 0
Entonces la respuesta definitiva es:
$$\lim_{x \to \frac{1}{2}^+}\left(\frac{2 x - 1}{x^{2} + \left(x + 1\right)}\right) = 0$$