1. The problem statement, all variables and given/known data Two point charges lie on the x axis. A charge of +8.4 µC is at the origin, and a charge of -3.8 µC is at x = 10.0 cm. At what position x would a third charge q3 be in equilibrium? 2. Relevant equations F=(kq1 q2)/r^2 3. The attempt at a solution I think that my main problem was that I wasn't quite sure how to solve for the distance if I don't have the charge for the third particle or its relation to the other charges.