1. The problem statement, all variables and given/known data 2. Relevant equations V=IR 3. The attempt at a solution I believe my a1 and a2 are correct. But my b1 is definitely wrong. Even if I carry out the above subtraction for the v1 part (which gives you b1) I will not have somethign as simple as R2 + R3 on the numerator Where would be some starting places to pinpoint the error?