[tex]\mathrm{Factor\:out\:common\:term\:}9 \ \textgreater \ 9\left(x^4-25y^8\right)[/tex]
[tex]Factor \ \textgreater \ x^4-25y^8[/tex]
[tex]\mathrm{Apply\:difference\:of\:squares\:rule:\:}x^2-y^2=\left(x+y\right)\left(x-y\right)[/tex]
[tex]x^2-5y^4=\left(x+\sqrt{5}y^2\right)\left(x-\sqrt{5}y^2\right)[/tex]
[tex]x^2-5y^4 \ \textgreater \ \mathrm{Apply\:difference\:of\:squares\:rule:\:}x^2-y^2=\left(x+y\right)\left(x-y\right)[/tex]
[tex]x^2-5y^4=\left(x+\sqrt{5}y^2\right)\left(x-\sqrt{5}y^2\right)[/tex]
[tex]\left(x^2+5y^4\right)\left(x+\sqrt{5}y^2\right)\left(x-\sqrt{5}y^2\right) [/tex]
[tex]9\left(x^2+5y^4\right)\left(x+\sqrt{5}y^2\right)\left(x-\sqrt{5}y^2\right)[/tex]
Hope this helps!
