Question

$2 \sqrt{2 \: - \sqrt{2 = \sqrt{2} } }$
explain this

Answer 1

Answer:

With an "=" sign under the radical sign, it makes no sense as it is.  Square roots of numbers make sense, but the square root of a logical proposition does not.

I suspect you might have a small typo.

Perhaps you meant:

2√2 - √2 = √2

which would make things much easier.