(x+1)√(x²-x-6) - 6(x+1) = 0
(x+1)(√(x²-x-6) - 6) = 0
x₁ = -1
√(x²-x-6) = 6
x² - x - 6 = 36
x² - x - 42 = 0
D = 1 + 168 = 169
x₂ = (1-13)/2 = -6
x₃ = (1+13)/2 = 7
Проверка:
x = -1
√(1 +1 - 6) = √-4 - не подходит
x = -6
√(36 + 6 - 6) = 6
7*6 = 36+6
42 = 42 - верно
x = 7
√(49 - 7 - 6) = √36 = 6
8*6 = 42 + 6
48 = 48 - верно
Ответ: -6 и 7