Question

Factorisation of y⁴ - 81x⁴

Answer 1

Answer:

(y²)² -(9x²)²

(y² + 9x²) ( y² - 9x²)

(y² + 9x²) { y² - (3x)²}

(y² + 9x²) ( y + 3x ) ( y - 3x)

Answer 2

Answer:

(y² + 9x²) (y² + 9x²)

Step-by-step explanation:

y⁴ - 81x⁴

= (y²)² - (9x²)² (identify by : (a+b) (a-b) = a² - b² )

= (y² + 9x²) (y² + 9x²)