1. (x^2-1)^2+(x^2-6x-7)^2=02. x^3+3x^2-x-3=0

Найдем корень уравнения.

1) (x - 1) + (x - 6 * x - 7) = 0; 

x - 6 * x 7 = 0;

D = b - 4 * a * c = (-6) - 4 * 1 * (-7) = 36 + 4 * 7 = 36 + 28 = 50 + 14 = 64 = 8;

x1 = (6 + 8)/2 = 14/2 = 7;

x2 = (6 8)/2 = -2/2 = -1;

Получаем:

(x - 1) + ((x 7) * (x + 1)) = 0; 

Нет корней.

2) x^3 + 3 * x^2 x -  3 = 0;

Разложим на множители, способом сортировки.

(x^3 + 3 * x^2) (x + 3) = 0;

x * (x + 3) (x + 3) = 0; 

(x + 3) * (x - 1) = 0;

(x + 3) * (x 1) * (x + 1) = 0;

x + 3 = 0;

x 1 = 0;

x + 1 = 0;

x = -3;

x = 1;

x = -1.