Tomamos como el límite
$$\lim_{x \to 5^+}\left(\frac{\left(- 5 x + \left(x^{2} + 24\right)\right)^{2}}{\left(x + 1\right)^{2}}\right)$$
cambiamos
$$\lim_{x \to 5^+}\left(\frac{\left(- 5 x + \left(x^{2} + 24\right)\right)^{2}}{\left(x + 1\right)^{2}}\right)$$
=
$$\lim_{x \to 5^+}\left(\frac{\left(x^{2} - 5 x + 24\right)^{2}}{\left(x + 1\right)^{2}}\right)$$
=
$$\lim_{x \to 5^+}\left(\frac{\left(x^{2} - 5 x + 24\right)^{2}}{\left(x + 1\right)^{2}}\right) = $$
$$\frac{\left(- 25 + 24 + 5^{2}\right)^{2}}{\left(1 + 5\right)^{2}} = $$
= 16
Entonces la respuesta definitiva es:
$$\lim_{x \to 5^+}\left(\frac{\left(- 5 x + \left(x^{2} + 24\right)\right)^{2}}{\left(x + 1\right)^{2}}\right) = 16$$