I need help with A and B, will upvote. Thanks

Part A A point charge q1 = 4.10 nC is placed at the origin, What is the potential energy of the system of the three charges if 93 is placed at & = + 10.0 cm? and a second point charge q2 = -3.10 nC is placed on the x-axis at x = + 21.0 cm. A third point Express your answer in joules. charge q3 = 2.10 nC is to be placed on the c-axis between q1 and q2. (Take as zero the potential energy of the three charges when they are infinitely IVO AEd OF ] ? far apart.) U = Submit Request Answer Part B Where should 93 be placed between qi and q2 to make the potential energy of the system equal to zero? Express your answer in centimeters. IVO AEQ cm