A charge of -3.95 nC and a charge of -5.00 nC are separated by a distance of 30. Find the position at which a third charge of +8.

A charge of -3.95 nC and a charge of -5.00 nC are separated by a distance of 30.0 cm. Find the position at which a third charge of +8.00 nC can be placed so that the net electrostatic force on it is zero. How many cm from the -3.95 nC charge and how many cm from the -5.00 nC charge?