1. The problem statement, all variables and given/known data 2. Relevant equations There's not much to write here except parallel resistors equation. This is supposed to be a superposition problem. How did he use a source transformation because I have no idea why and where he did the equivalent resistor and why did a current source turn into a voltage source...? Especially the placement of that voltage source. What happened? 3. The attempt at a solution Don't say stuff like "figure it out yourself" or give me hints because I have NO clue what to do. I don't care about the answer since it's given , I want to UNDERSTAND what is happening. Thanks.