$$x+\frac{1}{x^{3}}=30;x+\overline{x}=?$$
$x=\sqrt[3]{15-4\sqrt{14}}\approx 0.321949212\text{, }y=\sqrt[3]{4\sqrt{14}+15}+\sqrt[3]{15-4\sqrt{14}}\approx 3.428029182$
$x=\sqrt[3]{4\sqrt{14}+15}\approx 3.10607997\text{, }y=\sqrt[3]{4\sqrt{14}+15}+\sqrt[3]{15-4\sqrt{14}}\approx 3.428029182$
