Find a formula for the inverse, that is find LaTeX: \displaystyle f^{-1}(x) if LaTeX: \displaystyle f(x)=\frac{- 8 x - 6}{3 x - 2} .

LaTeX: \displaystyle f^{-1}(x)=\frac{2 \left(x - 3\right)}{3 x + 8}