If we can write a polynomial in the form [tex]a^2-b^2[/tex], then we can factor it as:
[tex]a^2-b^2=(a-b)(a+b)[/tex]
In this problem, we have the following expressions:
[tex]1. \ y^5 - 25 \\ \\ 2. \ 9m^2n^2-121 \\ \\ 3. p^{18} - q^{10} \\ \\ 4. 16r^2 - 27[/tex]
[tex]9m^2n^2-121 =3^2m^2n^2-11^2 \\ \\ =(3mn)^2-11^2 =(3mn-11)(3mn+11)[/tex]
So we could write 2 as a difference of squares.
[tex]p^{18} - q^{10}=(p^9)^2-(q^5)^2=(p^9-q^5)(p^9+q^5) \\ \\ \\ Remember: \ (a^m)^n=a^{mn}[/tex]
So we could write 2 as a difference of squares.