Final answer:
The expanded form of 12^6 is 12 x 12 x 12 x 12 x 12 x 12, which shows the base number 12 being multiplied by itself six times.
Step-by-step explanation:
When expressing 126 in expanded form we show it as multiple factors of the base number, 12, being multiplied together. Since the exponent is 6, we multiply the base number by itself six times. Therefore, the correct expanded form of 126 is 12 x 12 x 12 x 12 x 12 x 12.