Ответ:

x1 = -2 ; x2 = (3 - √21) / 2 ; x3 = (3 + √21) / 2;

Объяснение:

x^3 - x^2 - 9x - 6 = 0

(x+2)(x^2 - 3x - 3) = 0

=> x1 = -2 ; x2 = (3 - √21) / 2 ; x3 = (3 + √21) / 2;