1. The problem statement, all variables and given/known data Derive TEC between terminals "ab". 2. Relevant equations 3. The attempt at a solution I figured I'd add the mutual inductances to the inductors, and solve it as a normal RLC circuit, since no current is passing through the 80j coil, it's inductance wouldn't change. The 50j coil becomes an 80j coil (50j + 30j) and the 40j coil becomes a 70j coil (40j + 30j). Setting the voltage source to zero yields a thevenin resistance of -60 + 60j and KVL yields to a Thevenin voltage of 9 + 41j volts. However the answer says Rth = 60 + 60j and Vth = 9 + 51j. Can anyone help me identify where I went wrong? Thank you in advance.