P3=I3²*R3
I3=I1*R2/(R2+R3)
I1=U/R
R=R1+R2*R3/(R2+R3)=2+8*8/(8+8)=2+4=6 Ом
I1=36/6=6 A
I3=6*8/(8+8)=48/16=3 A
P3=3²*8=9*8=72 Вт
P3=I3²*R3
I3=I1*R2/(R2+R3)
I1=U/R
R=R1+R2*R3/(R2+R3)=2+8*8/(8+8)=2+4=6 Ом
I1=36/6=6 A
I3=6*8/(8+8)=48/16=3 A
P3=3²*8=9*8=72 Вт