Question

Factorise:

x³ + 125y³ + 2x + 10y

Answer 1

Given expression: x³ + 125y³ + 2x + 10y

⇒ (x³ + 125y³) + x³ + (5y)³

= (x + 5y) (x² – 5xy + 25y²)

⇒ x³ + 125y³ + 2x + 10y

= (x + 5y) (x² – 5xy + 25y²) + 2x + 10y

= (x + 5y) (x² – 5xy) + 25

Factor x + 5y

= (x + 5y) [x² – 5xy + 25y² + 2]