Solving a problem in physics section 59 paragraph 35 e

Solving a problem in physics section 59 paragraph 35 e

35. Identical charges Q = 3,0 nC located at the vertices of an equilateral triangle. What is the charge q1 should be placed in the center of the triangle to the resultant force acting on each charge, has become zero?

Additional information:

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)