Question

Factorise the following:

121x² – 169y²

Answer 1

The given expression is,

121x² – 169y²

Here we use the identity

a² – b² = (a + b)(a – b)

Taking a = 11x and b = 13y, we get

∴ 121x² – 169y²

= (11x)² – (13y)² 

= (11x – 13y)(11x + 13y)

Therefore, the factors of the given expression are (11x – 13y)(11x + 13y)