Question

разложите не множители x^3-x^2-9x+9

Answer 1

$x^3-9x+9-x^2 \ x(x^2-9)+(9-x^2) \ x(x-3)(x+3)+(3-x)(3+x) \ x(x-3)(x+3)+(3-x)(x+3) \ (x+3)(x(x-3)+(3-x)) \ (x+3)(x^2-3x+3-x) \ (x+3)(x^2-4x+3) \ x^2-4x+3 \ D=16-4*3 = 4 \  x_{1,2} = frac{4pm2}{2} \ x_1 = 3; x_2 = 1 \ (x-3)(x-1)(x+3)$