A classmate solved 3x = 12 by multiplying both sides by 3 and then dividing by x, claiming x = 4. Which evaluation best describes the mistake and why?

The error is numerical; multiplying first required adding a negative value to restore balance.

The classmate used an incorrect order of operations and divided by the variable instead of dividing both sides by 3.

The classmate incorrectly applied the scale analogy by changing only one side.

The classmate’s steps were valid because inverse operations preserve equality.