What is the difference between 12√2 and 12? What is the difference between 6√2 and 6?

Answer 1

well, just subtract

6√2 - 6 = 6(√2-1)

On the other hand, if you're just asking about the nature of the difference,

6√2 is 6 times √2
6 is just 6

what is the difference between 6*3 and 6?
same question, different numbers.

Not sure just what is confusing you here. √2 is a number like any other. It has no exact decimal representation, but its exact value is . . . √2