Question

factorise X^4 - 81 y^4

Answer 1

I hope it will help you

Answer 2

Your Answer.

Factorise_

$\mathsf{x^4 \:- \:81 y^4}$

(x²)² - 3⁴ y⁴

(x²)² - (3²y²)²

(x²)² - (9y²)²

Using a² - b² = (a + b) (a +
- b)

(x² + 9y² ) (x² - 9y² )