Giúp mình với ạ, mình cảm ơn

Đáp án:

 $1) x²-xy+x-y$

$= (x²+x)-(xy+y)$

$= x.(x+1)-y.(x+1)$

$= (x-y).(x+1)$

$2) 3x²-3xy-5x+5y$

$= (3x²-3xy)-(5x-5y)$

$= 3x.(x-y)-5.(x-y)$

$= (3x-5).(x-y)$

$3) x³-2x²+x$

$= x.(x²-2x+1)$

$= x.(x-1)²$

$4) x²-2xy+y²-16$

$= (x²-2xy+y²)-16$

$= (x-y)²-4²$

$= (x-y+4).(x-y-4)$

$5) 2x²+4x+2-2y²$

$ = 2.(x²+2x+1-y²)$

$= 2.[(x²+2x+1)-y²]$

$= 2.[(x+1)²-y²]$

 $= 2.(x+1-y).(x+1+y)$