Prima data ridici toata ecuatia la puterea a 3-a. Ridicand toata ecuatia la puterea a 3-a iti dispare radicalul de ordin 3 iar ecuatia va deveni : [tex] x^{2} - x - 3 = -1 [/tex]. Iar acum ai de rezolvat o ecuatie de gradul 2:
[tex] x^{2} - x - 3 = -1 =\ \textgreater \ x^2 - x - 3 + 1 = 0 =\ \textgreater \ x^2 - x - 2 = 0
D=b^2-4ac = (-1)^2 - 4 *1 * (-2) = 1 + 8 = 9
x_{1} = \frac{-b + \sqrt{D} }{2a} = \frac{1 + \sqrt{9} }{2} = \frac{1 + 3}{2} = \frac{4}{2} = 2
x_{2} = \frac{-b - \sqrt{D} }{2a} = \frac{1 - \sqrt{9} }{2} = \frac{1 - 3}{2} = \frac{-2}{2} = -1[/tex]
