Respuesta :

altavistard

Answer:

Step-by-step explanation:

Either memorize these two formulas, or derive them through multiplying r - q by r - q.

(r - q)^2 = r^2 - 2qr + q^2, and

(r + q)^2 = r^2 + 2qr + q^2    This is the square of the binomial (r + q).