1)
R1=R2=R4=R5=1 Ω
R3= 9 Ω
Rab=?
Rab=(((R1+R2) || R3) + R5) || R4
R123=((R1+R2)*R3)/(R1+R2+R3)
R123=2*9/11
R123=18/11 Ω
Rab=(R123+R5)||R4
Rab=((18/11+1)*1)/((18/11) + 2)
Rab=0,725 Ω
2)
R1=R2=R4=R5=1 Ω
R3= 9 Ω
Rac=?
Rab=(R1+R2)||R3||(R5+R4)
R123=((R1+R2)*R3)/(R1+R2+R3)
R123=2*9/11
R123=18/11 Ω
Rac=R123||(R4+R5)
Rac=((18/11)*2)/((18/11) + 2)
Rac=0,9 Ω