x(x^2+6x+9)=4(x+3);
x^3 + 6x^2 + 9x = 4x + 12;
x^3 + 6x^2 + 9x - 4x - 12 = 0;
x^3 - x^2 + 7x^2 - 7x + 12x - 12 = 0;
x^2*(x-1) + 7x*(x-1) + 12*(x-1) = 0;
(x-1)*(x^2 + 7x + 12) = 0;
(x-1)*(x^2 + 4x + 3x + 12) = 0;
(x-1)*(x*(x + 4) + 3*(x + 4)) = 0;
(x-1)*(x + 4)*(x + 3) = 0;
x - 1 = 0
x + 4 = 0
x + 3 = 0
ответ: X1 = -4; X2 = -3; X3 = 1.
