Question

factorise (x-2y)²-5(x-2y)+6

Answer 1

let (x-2y) = z
then , z²-5z+6
z²-3z-2z+6 = z(z-3)-2(z-3) = (z-3)(z-2)
substitute z in above equation,
(x-2y-3)(x-2y-2)
hope this helps

Answer 2

(x-2y-2)(x-2y-3)

HOPE IT HELPS