Twо chаrges аre lоcаted оn the x axis: q1 = +4.7 μC at x1 = +3.6 cm, and q2 = +4.7 μC at x2 = -3.6 cm. Two other charges are located on the y axis: q3 = +2.3 μC at y3 = +4.4 cm, and q4 = -8.7 μC at y4 = +6.6 cm. Find the magnitude and the direction of the net electric field at the origin.