Solve the all given parts of following problem:
Problem: A point charge q1=4.0 uC is at the origin and a point charge q2=6.0 uC is on the x axis at x=3.0 m.
Part A: find the eclectic force on charge q2.
Part B: Find the electric force on q2.
Part C: How would your answers for parts a and b change is q2 were -6.0 uC?
I known the correct answer but I need to know how to get that. Thanks in advance!