5. Решите уравнение: A) (2x - 5)² - (2x - 3)(2x + 3) = 0; Б) 9y² - 25 = 0.

Решение:

• A) \((2x - 5)^2 - (2x - 3)(2x + 3) = 0\)
  \((4x^2 - 20x + 25) - (4x^2 - 9) = 0\)
  \(4x^2 - 20x + 25 - 4x^2 + 9 = 0\)
  \(-20x + 34 = 0\)
  \(-20x = -34\)
  \(x = \frac{-34}{-20} = \frac{17}{10} = 1.7\)
• Б) \(9y^2 - 25 = 0\)
  \(9y^2 = 25\)
  \(y^2 = \frac{25}{9}\)
  \(y = \pm \sqrt{\frac{25}{9}} = \pm \frac{5}{3}\)

Ответ: A) x = 1.7; Б) y = ± 5/3.