$$\lim_{x \to 1^-}\left(\left(5 x - 1\right) \left(5 x + 1\right)\right) = 24$$
More at x→1 from the left$$\lim_{x \to 1^+}\left(\left(5 x - 1\right) \left(5 x + 1\right)\right) = 24$$
$$\lim_{x \to \infty}\left(\left(5 x - 1\right) \left(5 x + 1\right)\right) = \infty$$
More at x→oo$$\lim_{x \to 0^-}\left(\left(5 x - 1\right) \left(5 x + 1\right)\right) = -1$$
More at x→0 from the left$$\lim_{x \to 0^+}\left(\left(5 x - 1\right) \left(5 x + 1\right)\right) = -1$$
More at x→0 from the right$$\lim_{x \to -\infty}\left(\left(5 x - 1\right) \left(5 x + 1\right)\right) = \infty$$
More at x→-oo