Answer
$$\frac{3x-4+x^2}{3x^2\left(3x-4\right)}$$
Work Step by Step
Creating like denominators in order to simplify, we find:
$$\frac{1}{3x^2}+\frac{1}{3\left(3x-4\right)} \\ \frac{3x-4}{3x^2\left(3x-4\right)}+\frac{x^2}{3x^2\left(3x-4\right)} \\ \frac{3x-4+x^2}{3x^2\left(3x-4\right)}$$