The root number 12 is equal to the number 4 times the root number 3, that is, 2 and 3.
Similarly, the root number 48 can also be multiplied by the root number 3 as the root number 16, which means four root numbers 3.
If you multiply the numbers in the symbol, you can multiply them by the root sign first, or divide them.
Addition and subtraction can't move like this