Respuesta :
x*x is always a perfect square.
here x = a-b
so,
(a − b)(a − b) is ALWAYS a perfect square trinomial .
here x = a-b
so,
(a − b)(a − b) is ALWAYS a perfect square trinomial .
so bc. (a-b)(a-b) =(a-b)^2 = a^2 -2ab +b^2 so this mean that this is a perfect square trinomial always