Ro=R1*R2/(R1+R2)+R3=4*12/(4+12)+3=6 Ом
Io=Uo/Ro=2А
U3=Io*R3=6В
U1=U2=Uo-U3=6В
I1=U1/R1=6/4А
I2=U2/R2=1/2А
P1=U1^2/R1=9Вт
P2=U2^2/R2=3Вт
P3=U3^2/R3=12Вт
Ro=R1*R2/(R1+R2)+R3=4*12/(4+12)+3=6 Ом
Io=Uo/Ro=2А
U3=Io*R3=6В
U1=U2=Uo-U3=6В
I1=U1/R1=6/4А
I2=U2/R2=1/2А
P1=U1^2/R1=9Вт
P2=U2^2/R2=3Вт
P3=U3^2/R3=12Вт