$$3 x ^ { 3 } + 6 y ^ { 2 } x = 1 y = - 1$$
$x = \frac{18 ^ {\frac{2}{3}} {(\sqrt[3]{\sqrt{105} - 3} - \sqrt[3]{\sqrt{105} + 3})}}{18} = -0.16444326327490388$
$y=-1$
$y=-1$
$x=\sqrt[3]{\frac{\sqrt{105}}{18}-\frac{1}{6}}-\sqrt[3]{\frac{\sqrt{105}}{18}+\frac{1}{6}}$
