1. The problem statement, all variables and given/known data I must solve for the voltage across the resistor labelled R1 in the circuit above. The values given are the resistance of each resistor, the voltage of each voltage source and the current of the current source. Note: If referring to circuit loops consider them as being numbered from left to right starting in top-left. 2. Relevant equations Kirchhoff's Voltage Law Kirchoff's Current Law ? 3. The attempt at a solution I'm really not sure what the proper way is to approach this problem. Kirchoff's current and voltage law confuse me. I've done abstract loop analysis in circuits before such as this example: but we've never had to solve for any values. Also how is the current source I1 in the first picture treated in a loop equation such as the ones in the second picture? So far I've come up with loop equations for the circuit. I think I can then get a solution for the currents with simultaneous equations and then calculate the voltage through R1 from that. My main problem is I don't know what to do with the current source I1.