System is in equilibrium

When a system is at equilibrium.

Two electrons and a positive charge q are hold along a straight line. At what position and for what value of q will the system be in equilibrium.

The ratio of q and Q so as to make the system in equilibrium is

For a system in equilibrium, DeltaG=0 , under conditions of constant

For a system in equilibrium, DeltaG = 0 under conditions of constant :