Problem 4.6-2

 

We have the following circuit

From the left loop we have:

v1 = v +v0

From the right loop we have:

v2 = v0 – v’

But we have v = 4*(i2 – i1) = 4 V

vo = 8*(i2 – i3) = - 8V

and v’ = 10*(i3 – i1) = 20 V

Thus we get v1 = 4 – 8 = - 4V

And v2 = - 8 – 20 = - 24V

And finally we get R = (v + v’)/i1 = 24/2 = 12Ω