Decomposition factor: (2x + y) ^ 2-4x-2y + 1

Decomposition factor: (2x + y) ^ 2-4x-2y + 1

solution
(2x+y)²-4x-2y+1
=(2x + y) & # - 2 (2x + y) + 1 -- Take 2x + y as a whole
=[(2x+y)-1]²
=(2x+y-1)²