The value of (a - b - c)(a - b + c) is:

1. a² + b² + c² + 2ab

2. a² + b² - c² - 2ab

3. a² + b² + c² - 2ab

4. a² + b² - c² + 2ab

Use direct method to evaluate the following product:

(a - 8) (a + 2)

Use direct method to evaluate the following product:

(3x - 2y) (2x + y)

Use direct method to evaluate the following product:

(5a + 16) (3a - 7)