Pemfaktoran (x-2)²+(x-1)²-(x)² adalah.... Please jawab pakai jalannya!

(X-2)^2+(x-1)^2-x^2
(X-2)(x-2)+(x-1)(x-1)-x^2
(x^2-2x-2x+4)+(x^2-x-x+1)-x^2
(X^2-4x+4)+(x^2-2x+1)-x^2
X^2+x^2-x^2-4x-2x+4+1
X^2-6x+5