1. The problem statement, all variables and given/known data We have the problem in the figure where E1= 9 V,E3= 5 V,E8=-5 V,J5= 3 A,J7=-1 A. R1= 8 Ohm,R2= 6 Ohm,R3= 6 Ohm,R4=7 Ohm, R6= 5 Ohm, R8= 1 ohm. 2. Relevant equations I have to find the currents and the potential in the elements using KVL and KCL. 3. The attempt at a solution I know how to solve this,but the problem is the arrow in the left,near E8.Does that mean that the current should be always directed from the right to the left? WITHOUT taking this in consideration I have found the current first in R8. I8= E8/R8=-5/1= -5 A In the nod 1 I6+I8=J7 -5+I6=-1 and so I6= 4 A In the nod 2 I1=E1/R1=9/8 A I4+I6=I1 so I4+4=9/8 so I4=-23/8 A. To find R2 I apply KVL in the upper left part of the circuit and I have R4I4- R2I2+R1I1+E1=0 Remember,I havent taken in consideration the fact that the direction of the current should always be from right to lef.