The expression shown in the image is $9 - y^2$.

This is a difference of squares, which can be factored as:

$9 - y^2 = (3 + y)(3 - y)$

Would you like further details on factoring, or do you have additional questions about this expression?

Here are some related questions:

1. How would you factor a general difference of squares, like $a^2 - b^2$?
2. Can you apply this factoring technique to more complex polynomials?
3. What happens if the expression is not a difference of squares, but a sum of squares?
4. How would you solve $9 - y^2 = 0$ for $y$?
5. How is factoring useful when solving quadratic equations?

Tip: Recognizing patterns like the difference of squares can make factoring and solving equations much faster!