R1,R2,R3-параллельны 1/R123=1/R1+1/R2+1/R3 R123=120 Ом U123=R123*I=120*1=120 B I1=U123/R1=120/400=0.3 A
I2=120/300=0.4 A
I3=120/400=0.3 A
R4,R5- параллельны 1/R45=1/R4+1/R5 R45=100 ом
U45=R45*I=100*1=100 B I4=U45/R4=100/300=0.33 A
I5=100/150=0.67 A
UU123+U45=120+100=220 B