9. Suppose a cell has only sodium and potassium channels (no leak channels), with Nernst potentials ENa-+50 mV and Ex = -80 mV. If, at rest, GK is 10 times Gra, what is the resting membrane potential? To answer this question, use the equivalent circuit version of the Goldman equation (top equation of Nicholls, p. 106, or see the posted powerpoint from lecture): V = G Na E Na + GREK rest G Na + Gx (Hint: use that GR=10*GNa in the formula above and simplify your expression.)