Problem 1
In series: 10 + 2 = 12Ω
1 1 −1
+ � = 4Ω
12 6
In series: 4 + 8 = 12Ω
1 1 −1
In parallel: � + � = 4Ω
12 6
In series: 4 + 4 = 8Ω
1 1 −1
In parallel: � + � = 4Ω
8 8
In series: 4 + 6 = 10Ω
1 1 −1
In parallel: � + � = 4.44Ω
10 8
In parallel: �