The given expression is:

$36 - y^2$

This is a difference of squares, which follows the formula:

$a^2 - b^2 = (a - b)(a + b)$

Here, we recognize:

$36 = 6^2 \quad \text{and} \quad y^2 = y^2$

So, applying the difference of squares formula:

$36 - y^2 = (6 - y)(6 + y)$

Final Answer:

$(6 - y)(6 + y)$

Would you like a more detailed explanation or have any questions?

Related Questions:

1. How do you factor other types of quadratic expressions?
2. What is the difference of squares rule, and when is it used?
3. Can you give another example of factoring a difference of squares?
4. How do you factor expressions that are not perfect squares?
5. How can factoring be used to solve quadratic equations?

Tip:

Whenever you see a subtraction between two perfect squares, try using the difference of squares formula!