1. Factoring a negative out of a radical

How do you factor the Minus Sign out of the radical
$
1-\sqrt{1-x}
$

How do you factor the Minus Sign out of the radical
$
1-\sqrt{1-x}
$
I think you are looking to do this

$1-\sqrt{1-x}$

$1-\sqrt{-1(x-1)}$

If you know complex numbers then...

$1-\sqrt{-1}\sqrt{(x-1)}$

$1-i\sqrt{(x-1)}$