factor completely w^4-2401
\(w^4-2401=(w^2)^2-49^2=(w^2-49)(w^2+49)=(w^2-7^2)(w^2+49)\\\\=(w-7)(w+7)(w^2+49)\\\\------------------------------\\\\a^2-b^2=(a-b)(a+b)\)
\(w^4-2.401 \\ =(w^2+49)(w^2-49) \\ =(w^2+49)(w-7)(w+7)\)
