1. The problem statement, all variables and given/known data I remember in physics class that we saw this set up.The ratio of r1/r4=r2/r3 is the same. There is no use for the current to head through R5 if it's the same energy on both sides. Now in linear I have no idea how to use this. 2. Relevant equations !?! 3. The attempt at a solution I tried re-arranging Kirchhoff's laws, but it didn't give me enough variables to solve... Please help guys, I really can't figure this one out.