1. Разложите на множители: 1) a³ + 8b³; 2) x²y - 36y³; 3) -5m² + 10mn - 5n²; 4) 4ab - 28b + 8a - 56; 5) a⁴ - 81.

1) a³ + 8b³ = a³ + (2b)³ = (a + 2b)(a² - 2ab + 4b²) 2) x²y - 36y³ = y(x² - 36y²) = y(x - 6y)(x + 6y) 3) -5m² + 10mn - 5n² = -5(m² - 2mn + n²) = -5(m - n)² 4) 4ab - 28b + 8a - 56 = 4b(a - 7) + 8(a - 7) = (4b + 8)(a - 7) = 4(b + 2)(a - 7) 5) a⁴ - 81 = (a²)² - 9² = (a² - 9)(a² + 9) = (a - 3)(a + 3)(a² + 9)