x3-x+3x2y+3xy2+y3-y
= (x+y)3 + (x+y)
= (x+y) [(x+y)2+1]
= (x+y) (x2 + 2xy+y2 +1)
x3 - x + 3x2y + 3xy2 + y3 - y
= (x3 + 3x2y + 3xy2 + y3) - y - x
= (x + y)3 - (x + y) = (x + y) [(x + y)2 - 1]
= (x + y) (x + y - 1) (x + y + 1)
x3 -x+3x2y+3xy2+y3 -y
=(x3 +3x2y+3xy2+y3) -(x+y)
=(x+y)3 -(x+y)=(x+y)(x +2xy+y -1)=(x+y)[(x+y)2 -1]=(x+y)(x+y-1)(x+y+1)
k cho mik nha!