i1R1+i3R3=E1i_{1} R_{1}+i_{3} R_{3}=E_{1}i1R1+i3R3=E1
i4R4+i5R5−i3R3=0i_{4} R_{4}+i_{5} R_{5}-i_{3} R_{3}=0i4R4+i5R5−i3R3=0
−i4R4+i3R3+i6R6=E2-i_{4} R_{4}+i_{3} R_{3}+i_{6} R_{6}=E_{2}−i4R4+i3R3+i6R6=E2
i1R1+i4R4−i6R6=E1+E2i_{1} R_{1}+i_{4} R_{4}-i_{6} R_{6}=E_{1}+E_{2}i1R1+i4R4−i6R6=E1+E2