Two charges are fixed in place on the x-axis as shown. The charge at x = 0 is negative and has magnitude q = 2 µCoulombs (1 µCoulomb = 10-6 Coulombs). The charge at x = d, (d = +12 cm), is positive and has magnitude Q = 4 µCoulombs. Find a point x = xo along the x-axis at which the electric field is zero.