a) x(x - 2)(x + 2) - (x - 3)(x² + 3x +9) =x(x² - 4) - (x³ - 27) =
= x³ - 4x - x³ + 27 = 27 - 4x
б) 2a³ + 9 - 2(a + 1)(a² - a + 1) = 2a³ + 9 - 2(a³ + 1) = 2a³ + 9 - 2a³ - 2 = 7
a) x(x - 2)(x + 2) - (x - 3)(x² + 3x +9) =x(x² - 4) - (x³ - 27) =
= x³ - 4x - x³ + 27 = 27 - 4x
б) 2a³ + 9 - 2(a + 1)(a² - a + 1) = 2a³ + 9 - 2(a³ + 1) = 2a³ + 9 - 2a³ - 2 = 7