Question

Please see the attachment! (It seems to be simple but I can't seem to understand how the step changes)

Answer 1

How does it go from the first step to the second step?

Answer 2

very easy
4 can be expressed as 1+3
now look carefully \[\sqrt{1}+\sqrt{3}+2\sqrt{1}.\sqrt{3} = (1+\sqrt{3})^2\]

Answer 3

then further you can understand .!

Answer 4

Yes got it, thank you!