$${ x }^{ 3 } + { x }^{ 2 } +x=100$$
$x = \frac{2 ^ {\frac{2}{3}} {(\sqrt[3]{33 \sqrt{6729} + 2707} + \sqrt[3]{2707 - 33 \sqrt{6729}} - \sqrt[3]{2})}}{6} \approx 4.264429973$
