The Enthalpy of Hydration of AgBr Is -819 KJ$\omicron$

The enthalpy of hydration of AgBr is -819 kJ.mol^-1 at 25 ^$\omicron$ C .Given that the hydration enthalpy of Br^- is -309 kJ.mol^-1,Calculate the enthalpy of hydration of Ag⁺ ions.

A) -410 kJ.mol^-1
B) -819 kJ.mol^-1
C) -1128 kJ.mol^-1
D) -309 kJ.mol^-1
E) -510 kJ?mol^?1