Question

Factorise:

x³ – 216y³ – 3x + 18y

Answer 1

Given expression: x³ – 216y³ – 3x + 18y

⇒ (x³ – 216y³) – 3(x – 6y)

⇒ (x³ – 6y³) – 3(x – 6y)

We know that,

a³ – b³ = (a – b)(a² + ab + b²)

Hence,

⇒ (x – 6y) (x² + 6xy + 36y²) – 3(x – 6y)

⇒ (x – 6y) (x² + 6xy + 36y² – 3)