Suppose that the a system consisting of two charges 7 mC and –2 mC...

Suppose that the a system consisting of two charges 7 mC and –2 mC (and with no external field) placed at (–9 cm, 0, 0) and (9 cm, 0, 0) respectively is now placed in an external electric field E = A (1/${{r}^{2}}$ ); A = 9 × ${{10}^{5}}$ N${{C}^{-1}}{{m}^{2}}$. What would the electrostatic energy of the configuration be