Let f : $R \to R$ be the function defined by $f(x)=2x-3$ $\forall x \in R$.Write $f^{-1}.$
$\begin{array}{1 1} \large\frac{x-3}{2} \\\large\frac{2x}{3} \\ \large\frac{3x}{2} \\ \large\frac{x+3}{2} \end{array}$