Solve the following equation:

4x² - 25 = 0.

Given, 4x² - 25 = 0.

⇒ (2x)² - (5)² = 0

By using, a² - b² = (a + b)(a - b) we get,

⇒ (2x + 5)(2x - 5) = 0

⇒ 2x + 5 = 0 or 2x - 5 = 0

⇒ x = $-\dfrac{5}{2} \text{ or } \dfrac{5}{2}$.

Hence, roots of the given equations are $-\dfrac{5}{2}, \dfrac{5}{2}$.