Odpowiedź:
[tex]x^3-2x^2-x=0\\\\x(x^2-2x-1)=0\\\\x=0\ \ \ \ \vee\ \ \ \ x^2-2x-1=0\\\\x^2-2x-1=0\\\\a=1\ \ ,\ \ b=-2\ \ ,\ \ c=-1\\\\\Delta=b^2-4ac\\\\\Delta=(-2)^2-4\cdot1\cdot(-1)=4+4=8\\\\\sqrt{\Delta}=\sqrt{8}=\sqrt{4\cdot2}=2\sqrt{2}\\\\x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-2\sqrt{2}}{2\cdot1}=\frac{2-2\sqrt{2}}{2}=\frac{\not2(1-\sqrt{2})}{\not2}=1-\sqrt{2}\\\\x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+2\sqrt{2} }{2}=\frac{2+2\sqrt{2}}{2}=\frac{\not2(1+\sqrt{2})}{\not2}=1+\sqrt{2}[/tex]
[tex]R\'ownanie\ \ ma\ \ 3\ \ rozwiazania\\\\x=0\ \ \ \ \vee\ \ \ \ x=1-\sqrt{2}\ \ \ \ \vee\ \ \ \ x=1+\sqrt{2}[/tex]