Which equation is correct for EMF: V-Ir or V=EMF-Ir?

[RoryP]

was just reading through my physics revision book when i noticed one of the equations for E.M.F
In class and the exams I am sure we used EMF= V-Ir, but the book said that V=EMF-Ir.
was just wondering which one was right so that i don't make a mistake in the future!
any help would be great!

 

[RoryP]

ignore that one guys, i just thought through it and it is V=EMF-Ir.
it has to be because the EMF is the maximum potential difference between 2 electrodes and the voltage is smaller than the EMF due to internal resistance!