Respuesta :

PROOF:

[tex]y^4-(y^2-9)(y^2+9)\\=y^4 -(y^4-81)\\=y^4-y^4+81\\=81[/tex]

And 81 is ALWAYS divisible by 9

Answer:

Its 9*9

Step-by-step explanation:

The equation equals 81 and 9*9=81.

Have a great day! :)