Question

Factorize:

1 – 27a3.

Answer 1

1 - 27a3

= (1)3 − (3a)3 [a3 – b3 = (a – b)(a2 + ab + b2)]

= (1 − 3a)(12 + 1 x 3a + (3a)2)

= (1 − 3a)(1 + 3a + 9a2)

Therefore, 1−27a3 = (1 − 3a)(1 + 3a + 9a2)