Question

Factorise (3a - b)(a + b) - (3a - b)²

Answer 1

Given,

$(3a-b)(a+b)-(3a-b)^{2}$

Take $(3a-b)$ common in the given expression

$(3a-b)[(a-b)-(3a-b)]$

$(3a-b)[a+b-3a+b]$

$(3a-b)(-2a+2b)$

Therefore, the factors of $(3a-b)(a+b)-(3a-b)^{2}$ is $(3a-b)(-2a+2b)$.