$8 = \frac{{2x(3x - 2)}}{2} \Rightarrow 3{x^2} - 2x - 8 = 0$$\Delta  = {( - 2)^2} - 4(3)( - 8) = 4 + 96 = 100$$\left\{ {\begin{array}{*{20}{c}}{{x_1} = \frac{{2 + \sqrt {100} }}{{3 \times 2}} = \frac{{2 + 10}}{6} = \frac{{12}}{6} = 2}\\{{x_2} = \frac{{2 - \sqrt {100} }}{{3 \times 2}} = \frac{{2 - 10}}{6} = \frac{{ - 8}}{6}}\end{array}} \right.$