Super-node question, one equation or two?

[orangeincup]

Homework Statement

Use the mesh current method to solve for the power dissipated

Homework Equations

v1+v2+..vn=0
i=v/R
p=i*v

The Attempt at a Solution

I was trying to solve the question using two equations,
eq1) 20=4*i1+i1
eq2) -90=9*i2+6*i2
eq3)i2-i1=6A...

So I obviously made a mistake since the 6A is doing nothing in my equations, and both equations 1 and 2 have no unknowns. Am I suppose to just use one equation, and use the super node as my second? How can I tell when I need to use only one equation?

 

[donpacino]

In both eq1 and eq2 you are missing the voltage drop Vo

 

[gneill]

You are asked to use mesh equations, so rather than a supernode, you want a supermesh. You should write one equation for the supermesh and one constraint equation tying the two "normal" mesh currents to the 6 A source.