How Do You Calculate Electric Potential with Opposite Charges?

[ngkamsengpeter]

A positive charge Q between two charge , a positive charge and a negative charge .Now I want to find the electric potential at the positive charge Q due to both the charges . The problem I am facing is do I need to minus the
electric potential due to charge positive with the electric potential due to charge negative . I have this problem because the electric potential is a scalar quantity , so if I minus it , it will look like it is a vector quantity .So do I need to minus it or add it together ?

 

[Dr.Brain]

Because Potential is a scalar quantitu , Vnet=V(+) + V(-) , that is summation of potential at that point due to positive charge + potential at that point due to negative charge , while writing the potential terms take the charge +Q or -Q as the case maybe...