Physics Electrostatics Level: Misc Level

Three point charges are placed at the following (x,y) coordinates; charge+5.0x10-6Cat(0,0.7m0, charge+7.0x10-6Cat(0.9m,0), and charge-5.0x10-6Cat (0.9m,0.7m).Calculate the electrical potential at the origin due to these three point charges.Take the zero of potential to be at infinity.