R45=R4*R5/(R4+R5)=10/2=5 Ом R245=R2+R45=4+5=9 Ом R36=R3+R6=4+4=8 Ом R23456=R245*R36/(R245+R36)=9*8/(9+8)≈4.2 Ом Ro=R1+R23456=8+4.2=12.2 Ом === Io=I1=U/Ro=80/12.2≈6.6 A U36=U-I1*R1=80-6.6*8=27.2 B I3=I6=U36/R36=27.2/8=3.4 A I2=I1-I3=6.6-3.4=3.2 A U45=I2*R45=3.2*5=16 B I4=U45/R4=16/10=1.6 A I5=I2-I4=3.2-1.6=1.6 A ======================