Question

Factorise completely b. (x + 2y)^4 - 1​

Answer 1

Question:-

Factorise completely :

(x + 2y)⁴ - 1

Answer:-

Using identity

a² - b² =(a+b) (a-b)

Here a = x+2y

b = 1

(x + 2y)⁴ - 1

= ((x + 2y)²)² - (1)²

= ((x + 2y)² - 1) ((x + 2y)² + 1)

= (x + 2y + 1)(x +2y - 1) (x² + 2ab + 4y² +1)

Identity to be remembered:

▪︎(a+b)² = a² + 2ab + b²

▪︎(a-b)² = a² - 2ab + b²

▪︎a²-b² = (a+b)(a-b)