Question

Factorise.

63a² − 112b²

Answer 1

63a² − 112b² 

On writing it as follows:

= 7(9a² − 16b²) 

= 7 [(3a)² − (4b)²]

Using the identity a² − b² = (a − b) (a + b)

= 7(3a − 4b) (3a + 4b)

= a² − b² 

= (a − b) (a + b)