Approach this problem exactly like the example in the PowerPoint file Chapter, slides 14 to 19.
a) Why do we not need a number for Q for the 3rd charge?
b) Write the expression for FL = Fr. Leave this in terms of variables: k, q, Q, and X.
c) Write the expression that remains after things cancel out. This should only be in terms of x.
d) Solve for x and keep 2 digits after the decimal point.