Assertion (A): 1003 x 997 = 999991

Reason (R): (a - b)(a + b) = a² - b²

1. Assertion (A) is true, Reason (R) is false.

2. Assertion (A) is false, Reason (R) is true.

3. Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct reason for Assertion (A).

4. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct reason (or explanation) for Assertion (A).

Find the expansions of the following :

(i) (2x + 3y + 5)(2x + 3y - 5)

(ii) (6 - 4a - 7b)²

(iii) (7 - 3xy)³

(iv) (x + y + 2)³

Evaluate 1002 × 998 by using a special product.

If a + 2b + 3c = 0, prove that a³ + 8b³ + 27c³ = 18abc.