Answer:
D [tex] \frac{1}{3} x - \frac{2}{3} [/tex]
Step-by-step explanation:
[tex] f(x) = 3x + 2[/tex]
[tex] {f}^{ - 1} (x) = \frac{x}{3} - \frac{2}{3} ⟹ \frac{1}{3} x - \frac{2}{3} [/tex]