4b2) = 3(a2 – 2b)(a2 + 2b)
б) – 3x2 +
24x – 48 = -3(x2 – 8x + 16) = -3(x – 4)2в) 27a3 + b3 = (3a + b)(9a2 – 3ab + b2)
№2 №3
x3 + 3x2 – 9x – 27 = 0
(x3 + 3x2 ) – (9x + 27) = 0
x2(x + 3) – 9(x+3) = 0
(x + 3)(x2 – 9) = 0
(x + 3)(x – 3)(x + 3) = 0
x + 3 = 0 или x – 3 = 0
x = -3 x = 3
Ответ: -3; 3.