## Simplifying the Expression (a^2 - 28)/(a - 5)

The expression (a^2 - 28)/(a - 5) represents a rational expression, which is a fraction where the numerator and denominator are polynomials. To simplify this expression, we can follow these steps:

**1. Factor the numerator:**

The numerator, a^2 - 28, is a difference of squares. We can factor it as:
**(a + √28)(a - √28)**

**2. Simplify the expression:**

Now we can rewrite the original expression as:
**(a + √28)(a - √28) / (a - 5)**

**3. Identify any restrictions:**

The expression is undefined when the denominator equals zero. Therefore, **a ≠ 5**.

**Final Simplified Expression:**

The simplified expression is:
**(a + √28)(a - √28) / (a - 5), where a ≠ 5**

**Note:**

- We can further simplify the expression by substituting √28 = 2√7.
- This simplified form allows us to easily identify the values of 'a' for which the expression is defined and undefined.
- The simplified expression can be used for various mathematical operations, such as solving equations, finding the domain and range, or analyzing the behavior of the expression.