1) 9m² - 12mn = 3m(3m - 4n)
2) 15x⁴ - 5x⁶ = 5x⁴(3 - x²)
3) 18х² + 12х²у² - 24ху² = 6x(3x + 2xy² - 4y²)
4) ах + ау + 7у + 7х = a(x + y) + 7(x + y) = (a + 7)(x + y)
5) а² - 49 = a² - 7² = (a - 7)(a + 7)
9х² - 6ху + у² = (3x)² - 2 * 3xy + y² = (3x - y)²