Respuesta :
p(p - q) - q(q - p). Multiply out.
p*p - p*q - q*q + q*p.
Note because of the minus before the bracket, the minus inside the bracket changes to +
p² - pq -q² + pq
p² - q² + pq - pq
p² - q² + 0
p² - q²
= p² - q²
I hope this helps.
p*p - p*q - q*q + q*p.
Note because of the minus before the bracket, the minus inside the bracket changes to +
p² - pq -q² + pq
p² - q² + pq - pq
p² - q² + 0
p² - q²
= p² - q²
I hope this helps.