A point charge q1q1 = 4.10 nCnC is placed at the origin, and a second point charge q2q2 = -2.95 nCnC is placed on the xx-axis at x=+x=+ 20.0 cmcm. A third point charge q3q3 = 2.10 nCnC is to be placed on the xx-axis between q1q1 and q2q2. (Take as zero the potential energy of the three charges when they are infinitely far apart.) What is the potential energy of the system of the three charges if q3q3 is placed at x=+x=+ 10.5 cmcm?