Kirchhoff's Law - Finding i in non series/parallel circuit
You need to use both KCL and KVL.
Current i2= i4 - i3,
i3= i+4,
i5= i-10 = i4 + 2 --> i4 =i5 - 2 = i-12
therefore i2 = (i-12) - (i+4) = -16A

Vac = Vad + Vdc = -(i-10)*4 + -(i-12)*1 = 52 - 5i,
Vac = Vab + Vbc = 0 + (i+4)3
equating Vac we get i= 5A which implies Vac = 27V