The expression 9x^4 - 225y^8 can be factored as
using the difference of squares formula. This represents the product of two binomials, each corresponding to the sum and difference of square terms.
To factor the expression
, we can use the difference of squares formula:

In this case,
and
. We can rewrite the expression as:
![\[ 9x^4 - 225y^8 = (3x^2)^2 - (15y^4)^2 \]](https://img.qammunity.org/2018/formulas/mathematics/high-school/aau1sac7qe0ccncka3n8d6a901yi38c0zn.png)
Now, we can apply the difference of squares formula:
![\[ 9x^4 - 225y^8 = (3x^2 + 15y^4)(3x^2 - 15y^4) \]](https://img.qammunity.org/2018/formulas/mathematics/high-school/hdt4e78psv51d1tm461dsyhwhp2pf2j690.png)
So, the factored form is
.