Question

=Simplify/expand (a − b) (b − a)

=Simplify/expand (a − b) (b + a)

Answer 1

(a-b)(b-a) = -(a-b)(a-b) = -(a-b)^2 = -(a^2-2ab+b^2) ...

Recall that (a-b)(a+b) = a^2 - b^2