3. Решите уравнение: a) 8²-x²=0 б) 36y²-25=0 в) (5-x)²-x(x+6,5)=25

a) \(8^2 - x^2 = 0\) \(64 - x^2 = 0\) \(x^2 = 64\) \(x = \pm 8\) б) \(36y^2 - 25 = 0\) \(36y^2 = 25\) \(y^2 = \frac{25}{36}\) \(y = \pm \frac{5}{6}\) в) \((5-x)^2 - x(x+6,5) = 25\) \(25 - 10x + x^2 - x^2 - 6,5x = 25\) \(-10x - 6,5x = 0\) \(-16,5x = 0\) \(x = 0\)