a) (x - 3)² – 25x² = (x - 3 - 5x)(x - 3 + 5x) = (-4x - 3)(6x - 3) = -3(4x + 3)(2x - 1)
б) a² – b² – 4b – 4a = (a² - 4a) - (b² + 4b) = (a² - 4a + 4) - (b² + 4b + 4) = (a - 2)² - (b + 2)² = (a - 2 - b - 2)(a - 2 + b + 2) = (a - b - 4)(a + b)
в) 8 – y⁶ = (2 - y²)(4 + 2y² + y⁴)
Ответ: a) -3(4x + 3)(2x - 1); б) (a - b - 4)(a + b); в) (2 - y²)(4 + 2y² + y⁴)