How can i convert a equation into a working circuit
Let's look at your equation "Eb (Back EMF) = V - IR (Copper losses)". The back EMF is determined by the number of coils and the geometry of the magnetic fields. Copper loss is determined by the length and diameter of the copper wires. Can you easily change either of these things? Not without taking the motor apart and rebuilding it.

So the answer is, basically, that for a given motor these numbers are indeed constants. And the nature of constants is that you cannot change them. If you could change them they would be variables, but they are not.