Correct Answer: a ² + ab + b ²

Solution : Given: a – b = 1
We know the algebraic identity, a ³ – b ³ = (a – b)(a ² + ab + b ² )
Substitute the given value in the above formula and we get,
⇒ a ³ – b ³ = (1)(a ² + ab + b ² )
So, a ³ – b ³ = a ² + ab + b ²
Hence, the correct answer is a ² + ab + b ² .