Question

Factorise the following:

49x² – 25y² + 10y – 1

Answer 1

Given: 49x² – 25y² + 10y – 1

⇒ (7x)² – [(5y)² – 2 × 5y × 1 + 1²]

⇒ (7x)² – (5y – 1)²

We know that,

(a + b) (a – b) = a² – b²

Hence, 

⇒ (7x – 5y + 1) (7x + 5y – 1)