U2=I2*R2=3*12=36B=U1=U3=U4: I1=U1/R1=36/6=6A; I12=6A+3A=9A? найдем общее сопротивление R12=R1*R2/R1+R2=72/18=4 OM; R34=R3*R4/R3+R4=64/16=4 OM; R1234= R12*R34/R12+R34=16/8=2 OM; R=R1234+R5=2+3=5 OM; I3=U3/R3=36/8=4,5 A; I4=U4/R4=36/8=4,5A; I34=I3+I4=4,5+4,5=9A; I=I5=I12+I34=9+9=18A; U5=I5*R5=18*3=54B; U=U1+U5=54+36=90B
I=18A, U=90B
I1=6A; U1=36B
I2=3A; U2=36B
I3=4,5A; U3=36B
I4=4,5A; U4=36B
I5=18A; U5=54B