Answer :

[tex]6w^4-54w^2=6w^2(w^2-9)=6w^2(w^2-3^2)=6w^2(w-3)(w+3)[/tex]
[tex]6w^4-54w^2=6w^2\cdot w^2-6w^2\cdot9=6w^2\cdot(w^2-9)=6w^2(w-3)(w+3)[/tex]