Sqrt 80n^2 = sqrt 40x2xnxn = sqrt 20x2x2xnxn = sqrt 10x2x2x2xnxn = sqrt 5x2x2x2x2xnxn
Pull out numbers and letters in groups of 2
2x sqrt 5x2x2xnxn
2x2x sqrt 5xnxn
2x2xnx sqrt 5
Multiply the numbers and letters on the outside of the radical
4n x sqrt 5 is the final answer.
