Объяснение:
1) = a² + 2a + 3a + 6 = a² + 5a + 6
2) = c² - 3c - 10c + 30 = c² - 13c + 30
3) = 8a³ + 2ab² - 4ba² - b³
4) = (3x² + x - 6x - 2)(4x - 3) = (3x² - 5x - 2)(4x - 3) = 12x³ - 9x² - 20x² + 15x - 8x + 6 = 12x³ - 29x² + 7x + 6
