Facem subtitutia [tex]x=y+ \frac{2}{y} [/tex]. Ecuatia se scrie:
[tex](y+ \frac{2}{y} )^3-6(y+ \frac{2}{y} )-6=0\\
y^6-6y^3+8=0\\
y^3=z\\
z^2-6z+8=0\\
z= 4 sau 2\\
y^3=4=>y=\sqrt[3]{4}=>x=\sqrt[3]{4}+ \frac{2}{\sqrt[3]{4}} =\sqrt[3]{4}+\frac{\sqrt[3]{8}}{\sqrt[3]{4}}\\
x=\sqrt[3]{4}+\sqrt[3]{2}[/tex]
