$$7 { x }^{ 3 } -4+ { x }^{ 2 } +3=16$$
$x = \frac{2 ^ {\frac{2}{3}} {(\sqrt[3]{21 \sqrt{1146837} + 22489} + \sqrt[3]{22489 - 21 \sqrt{1146837}} - \sqrt[3]{2})}}{42} \approx 1.298186057$
