$$x(2x+2)^2 = 6$$
Answer
$$ \begin{matrix}x_1 = 0.59191 & x_2 = -1.29595+0.92449i & x_3 = -1.29595-0.92449i \end{matrix} $$
Explanation
$$ \begin{aligned} x(2x+2)^2 &= 6&& \text{simplify left side} \\[1 em]x(4x^2+8x+4) &= 6&& \\[1 em]4x^3+8x^2+4x &= 6&& \text{move all terms to the left hand side } \\[1 em]4x^3+8x^2+4x-6 &= 0&& \\[1 em] \end{aligned} $$
This polynomial has no rational roots that can be found using Rational Root Test.
Roots were found using qubic formulas.
This page was created using
Equations Solver