Slove `(3-sqrt(11)) (3+ sqrt(11))`

Answer

To solve the expression \((3 - \sqrt{11})(3 + \sqrt{11})\), we can use the difference of squares formula, which states that:

\[ (a - b)(a + b) = a^2 - b^2 \]

### Step-by-Step Solution:

1. **Identify \(a\) and \(b\)**:
- Here, \(a = 3\) and \(b = \sqrt{11}\).

2. **Apply the difference of squares formula**:
- Substitute \(a\) and \(b\) into the formula:
\[ (3 - \sqrt{11})(3 + \sqrt{11}) = 3^2 - (\sqrt{11})^2 \]

3. **Calculate \(3^2\)**:
- \(3^2 = 9\).

4. **Calculate \((\sqrt{11})^2\)**:
- \((\sqrt{11})^2 = 11\).

5. **Subtract the two results**:
- Now, substitute back into the equation:
\[ 9 - 11 = -2 \]

6. **Final Answer**:
- Therefore, \((3 - \sqrt{11})(3 + \sqrt{11}) = -2\).

### Summary of the Steps:
- Identify \(a\) and \(b\).
- Use the difference of squares formula.
- Calculate \(a^2\) and \(b^2\).
- Subtract \(b^2\) from \(a^2\) to get the final result.