1. The problem statement, all variables and given/known data I've obtained the node equations that's in the matrix for rows 1, 2, and 4. I got 3 as well but I'm not sure if my analysis was correct. http://img252.imageshack.us/img252/3151/nodeq.jpg [Broken] 3. The attempt at a solution http://img684.imageshack.us/img684/9803/dsc0010van.jpg [Broken] So basically this is from the bottom-left of the circuit. v1 = -2 + Vx, therefore Vx = v1 + 2 (I wrote -2 in the drawing by mistake) So doing KVL: -Vx + 2 + 5io + v2 = 0 => (-v1 -2) + 2 + v3 + v2 = 0 So, -v1 + v2 + v3 = 0 [which is row 3 of the matrix] Note that io = v3/5, so 5io is just v3. Is this correct reasoning?