I=E/R+r
R=R1+(R2*R3/R2+R3)+R4=24.6 Ом
I=100/24.6+1=3.9 A
U=E*R/R+r
U=100*24.6/24.6+1=96 B
I1=I4=I=3.9 A
U2.3=I2.3*R2.3=3.9*6.6=25.7 B
I2=U2.3/R2=25.7/15=1.7 A
I3=U2.3/R3=25.7/12=2.2 A
P=I^2*R1+I^2*R2+I^2*R3+I^2*R4
P=3.9^2*10+1.7^2*15+2.2^2*12+3.9^2*8=375.2 Вт