Answer
$\frac{-1\pm\sqrt {3}}{2}\approx- 1.366, 0.366$
Work Step by Step
Take logarithm on both sides to get $(x^2+x)ln3=\frac{1}{2}ln3 \longrightarrow 2x^2+2x-1=0 \longrightarrow x=\frac{-2\pm\sqrt {4+8}}{2(2)}=\frac{-1\pm\sqrt {3}}{2}\approx- 1.366, 0.366$
