Tomamos como el límite
$$\lim_{x \to 2^+}\left(\frac{- 7 x + \left(x^{2} + 10\right)}{- 9 x + \left(x^{2} + 20\right)}\right)$$
cambiamos
$$\lim_{x \to 2^+}\left(\frac{- 7 x + \left(x^{2} + 10\right)}{- 9 x + \left(x^{2} + 20\right)}\right)$$
=
$$\lim_{x \to 2^+}\left(\frac{\left(x - 5\right) \left(x - 2\right)}{\left(x - 5\right) \left(x - 4\right)}\right)$$
=
$$\lim_{x \to 2^+}\left(\frac{x - 2}{x - 4}\right) = $$
$$\frac{-2 + 2}{-4 + 2} = $$
= 0
Entonces la respuesta definitiva es:
$$\lim_{x \to 2^+}\left(\frac{- 7 x + \left(x^{2} + 10\right)}{- 9 x + \left(x^{2} + 20\right)}\right) = 0$$