Three point charges are placed on the x-axis. A charge of +2.0 ¦ÌC is placed at the origin, −2.0 ¦ÌC to the right at x=50 cm, and +4.0 ¦ÌC at the 100cm mark. What is the magnitude of the electrostatic force that acts on the charge at the origin? (k=1/4¦Ðϵ0=8.99¡Á109 N ¡¤ m2/C2)