two charged spheres 4 cm apart attract each other with a force of 1.2x10^-9 . determin the magnitude of the charge on each if one has twice the charge (of the opposite sign) as the other.
Fe = KQq/r^2
The Attempt at a Solution
well you are only given Fe and r, plus the info that Q is = to (2)q and k = 9.0x10^9 so im stumped after this step
1.2x10^-9 = (9.0x10^9)(2)qq/16