In the "Foundation Maths" book in chapter (19): "The exponential function", there was an example solving the following problem (I used "^" to denote power):

(e^2t + 2e^2 + 1)^1/2

In solving the problem, this was converted to ((e^t + 1)^2)^1/2

What clue can tell that I have to solve the problem this way and not by just taking the root of every element?

Thanks.