Two point charges are placed on the x-axis. The first charge,q1 = 8.00 nC, is placed a distance 16.0 m from the origin along the positive x-axis; the second charge, q2 = 6.00 nC, is placed a distance 9.00 m from the origin along the negative x-axis. Discover the magnitude and sign of q3 needed to build the total electric field at point A equal to zero.