Question

уравнения
b^3-b=0
x^3+x^2-x-1=0

Answer 1

$b^{3}-b=0 \ b(b^{2}-1)=0 \ b(b-1)(b+1)=0$
b=0 или  b-1=0 или b+1=0
              b=1          b=-1
$x^{3}-x+(x^{2}-1)=0 \ x(x^{2}-1)+1(x^{2}-1)=0 \ (x+1)(x^{2}-1)=0 \ (x+1)(x+1)(x-1)=0$
x+1=0 или x-1=0
х=-1          х=1