( x - 2)(x^2 + 6x + 9 ) - 6( x + 3) = 0
( x - 2)( x + 3)^2 - 6( x + 3) = 0
( x + 3)( (x-2)(x+3) - 6) = 0
( x + 3)( x^2 + x - 6 - 6) = 0
( x + 3)( x^2 + x - 12) = 0
x + 3 = 0
x = - 3
x^2 + x - 12 = 0
D = b^2 - 4ac = 1 + 48 = 49 = 7^2
x1 = ( - 1 + 7) / 2 = 3
x2 = ( - 1 - 7) / 2 = - 4
Ответ: x1 = 3, x2 = - 4, x3 = - 3.