Let RP be the equivalent resistance of the resistors 12Ω, 6Ω and 4Ω connected in parallel. Hence, we have
I/Rp = 1/12 + 1/6 + 1/4 = 1 + 2 + 3/12 = 1/2
Rp = 2Ω
Therefore, the equivalent resistance of the circuit is 2
2Ω + Rp + 5Ω = 2Ω + 5Ω = 9Ω
Thus, the equivalent resistance between points A and B is 9Ω.