Finding V0 when V0/4 = 10 + 2V0

[p75213]

I have been teaching myself electronics from "Fundamentals of Electric Circuits". Can somebody help me with the attached problem? I know the answer, as it is given in the back of the book. However the method used to arrive at the answer eludes me. The answer is -4.444V and 98.75W. I have been able to figure out subsequent problems but this one has me stumped.
I get the following equation for V0 -> V0/4=(10+2V0)

 

[Antiphon]

Check the definition of V0 on the diagram. It's not what you wrote in the equation.

 

[Chunkysalsa]

Yea, check your signs. Current goes through a resistor from high to low voltage, your equation has charges gaining energy from the resistor.

 

[p75213]

Thanks guys.

 

[flyingpig]

the picture is very confusing, what is the diamond voltage??

 

[p75213]

The diamond voltage is not necessary to figure out v0. The correct equation for v0 is v0/4=-10-2v0.