Вправи 1101 - 1165 » 1107

1107. Розклади на множники многочлен. a) a2 – 6ab + 8b2 = a2 – 2ab – 4ab + 8b2 = a(a – 2b) – 4b(a – 2b) = (a – 2b)(a – 4b); б) 2a2 + 7ab – 15b2 = 2a2 + 3ab – 10ab – 15b2 = a(2a + 3b) – 5b(2a + 3b) = (2a + 3b)(a – 5b); в) 6a2 + ab – b2 = 6a2 + 3ab – 2ab – b2 = 3a(2a + b) – b(2a + b) = (2a + b)(3a – b).