How do you simplify #sqrt 160#?
Factor perfect squares out of the square root until there are no more perfect squares inside.
Begin by working inside the square root itself. You can manipulate the interior of the square root as much as you'd like so long as you don't violate any other rules of algebra.
Because 16 is a perfect square, we can pull it out of the square root as a 4.
That will simplify down to