R1+R2=4 R4+R5=3+3=6 1/R1P=1/4+1/6+1/4=2/3 R1P=1.5
1/R2P=4/12=1/3 R2P=3 R1P+4=5.5
R7+R8=6 1/R3P=1/4+1/4=1/2 R3P=2 1/R4P=1/6+1/7=13/42 R4P=42/13=4
СЧИТАЕМ всю схему
1/х=1/4+1/10=7/20 х=20/7
20/7+3+2=55/7
1/8+7/55=111/440 х=440/111
R=440/111+1,5+4+3=440/111+8,5=12 103/222