Given:
[tex](9a^2-4)(9a^2+4)[/tex]The shown represents the difference between the squares
So, the product of the polynomials will be as follows:
[tex]\begin{gathered} (9a^2-4)(9a^2+4) \\ =(9a^2)^2-(4)^2 \\ =81a^4-16 \end{gathered}[/tex]So, the answer will be:
This simplifies to:
[tex]81a^4-16[/tex]The degree of our simplified answer is 4