$$( x + 2 ) ^ { 3 } = 2 x ( x ^ { 2 } - 1 )$$
$x = \frac{9 ^ {\frac{2}{3}} \sqrt[3]{26 {(\sqrt{3} + 9)}} + 9 ^ {\frac{2}{3}} \sqrt[3]{26 {(9 - \sqrt{3})}} + 18}{9} \approx 7.900267739$
