R, U, I, I1, I2, I3, U1, U2, U3—?
R1=7 Ом
R2=3 Ом
R3=6 Ом
I=I1=4 А​

R=R1+R2*R3/(R2+R3)=7+3*6/(3+6)=7+2=9 Ом

U=I*R=4*9=36 B

I1=I=4 A

U1=I1*R1=4*7=28 B

I2=I*R3/(R2+R3)=4*6/(3+6)=2,67 A

U2=U-U1=36-28=8 B

I3=I-I2=4-2,67=1,33 B

U3=U2= 8 B