Question

Factorise the following:

18ab³ – 8a³b

Answer 1

The given expression is,

18ab³ – 8a³b

= 2ab(9b² – 4a²)

 Here we use the identity,

x² – y² = (x + y)(x – y)

Taking x = 3b and y = 2a, we get

∴ 18ab³ – 8a³b

= 2ab(9b² – 4a²)

= 2ab(3b – 2a) (3b + 2a)

Therefore, the factors of the given expression are 2ab(3b – 2a)(3b + 2a)