Answer
$$x=\sqrt{\frac{11}{3}}+2,\:x=-\sqrt{\frac{11}{3}}+2$$
Work Step by Step
We complete the square to find:
$$3\left(x^2-4x+\frac{1}{3}\right) \\ 3\left(\left(x-2\right)^2+\frac{1}{3}-\left(-2\right)^2\right) \\ 3\left(x-2\right)^2-11 \\ x=\sqrt{\frac{11}{3}}+2,\:x=-\sqrt{\frac{11}{3}}+2$$
