Simplify the given expression.
(1 + x)3 + (1 - x)3 + (-2)3
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. - 6(1 - x2)
Formula used:
(a + b)3 = a3 + b3 + 3ab(a + b)
(a - b)3 = a3 + b3 - 3ab(a - b)
Calculations:
Using the above formula we get;
⇒ 1 + x3 + 3x + 3x2 + 1 - x3 - 3x + 3x2 - 8
⇒ 2 + 6x2 - 8
⇒ - 6 + 6x2
⇒ - 6(1 - x2)