Đáp án:
x^2 (x-2) + 4(2-x)
= x^2 (x-2) - 4(x-2)
= (x^2 -4) (x-2)
= (x-2)(x+2)(x-2)
= (x-2)^2 (x+2).
 

x^2 . (x - 2 ) + 4 . (2 - x)
= x^2 ( x - 2 ) + 4 ( 2 - x ) = x^2 ( x - 2 ) - 4 ( 2 - x )= ( x - 2 ).( x^2 - 4 )= (x - 2).(x - 2).(x + 2)$$\textit{Adolf Hitler}$$