$$\begin{gathered} {\mathrm{H}}_{2\left(\mathrm{g}\right)}+\frac{1}{2}{\mathrm{O}}_{2\left(\mathrm{g}\right)}\to {\mathrm{H}}_2{\mathrm{O}}_{\left(1\right)}; ∆\mathrm{H}=-286.2\mathrm{kJ}; \\ {\mathrm{H}}_2{\mathrm{O}}_{\left(1\right)}\to {\mathrm{H}}_{\left(\mathrm{aq}\right)}^{+}+{\mathrm{OH}}_{\left(\mathrm{aq}\right)}^{-}; ∆\mathrm{H}=+57.3 \mathrm{kJ} \end{gathered}$$

Calculate the enthalpy of ionization of OH^- in aqueous solution in kJ is -x what is the x value?