Two point charges are located along the x axis: q1 = +6.0 μC at x1 = +4.0 cm, and q2 = +6.0 μC at x2 = -4.0 cm. Two other charges are located on the y axis: q3 = +3.0 μC at y3 = +5.0 cm, and q4 = -8.0 μC at y4 = +7.0 cm. Find the net electric field (magnitude and direction) at the origin.