factor the following trinomail
w^18-9w^9y^5+14y^10
=w^18-7w^9y^5-2w^9y^5+14y^10=
(w^18-7w^9y^5)-(2w^9y^5-14y^10)=
w^9(w^9-7y^5)-2y^5(w^9-7y^5)=
(w^9-7y^5)(w^9-2y^5)
w^18-9w^9y^5+14y^10
(w^18-7w^9y^5)-(2w^9y^5-14y^10)=
w^9(w^9-7y^5)-2y^5(w^9-7y^5)=
(w^9-7y^5)(w^9-2y^5)