the H.C.F

Find the H.C.F of(x²+y²)(x²+2xy+y²),(x²-y²)³ and (x⁶-y⁶) 

$$\\(x^2+y^2)(x^2+2xy+y^2)\\ =(x^2+y^2)(x+y)^2\qquad (1)\\\\\\ (x^2-y^2)^3\\ =(x-y)^3(x+y)^3\qquad (2)\\\\\\ (x^6-y^6)=(x^3-y^3)(x^3+y^3)\\ =(x-y)(x^2+xy+y^2)(x+y)(x^2-xy+y^2)\qquad(3)\\\\\\ (x^2+y^2)(x+y)^2\qquad (1)\\ (x-y)^3(x+y)^3\qquad (2)\\ (x-y)(x^2+xy+y^2)(x+y)(x^2-xy+y^2)\qquad(3)\\\\\\ HCF= x+y$$

I think that is correct.