consider the voltage and current in the circuit and apply Ohm's law.
R = E / I
I = 12 / 8 = 1.5amp on the secondary
The 10:1 turns ratio tells us we have 1.5 amp / 10 = .15 amp in the primary
R = E / I = 120 / .15 = 800 Ohm
So our 10:1 turns has a 800 Ohm to 8 Ohm impedance match.
Another way of looking at it is R = E / I and when we reduce the voltage we have a higher current available. Reducing E reduces R AND increasing I reduces R.