# Equivalent Circuit of cell membrane potential

From chapter $$7$$ of Kandel et all's Principles of Neural Science:, Go to page 12, Box 7-2 (particular image attached below)

The author claims that $$V_m = E_{Na} + I_{Na} / g_{Na}$$ on one side of the equation and then says $$V_m = E_{K} + I_{K} / g_{K}$$ by looking at the other side of the circuit.

But how can this be? Since the battery is showing a negative side facing $$V_{in}$$ doesn't it have to be

$$V_m = -E_{K} + I_{K} / g_{K}$$

Am I misunderstanding something or did the author make a mistake in calculation?

Note that $$E_{K} = -75 mV$$. If you were to use instead your equation:
$$V_m = -E_{K} + I_{K} / g_{K}$$
you would need to take $$E_{K} = 75 mV$$ and you'd arrive at the same answer.