p3+ q3 = ?
(p + q)3
(p + q)(p2 + q2 + p q)
(p + q)(p2 + q2 – p q)
p3 + q3 + 3pq
We know the cubic identity, p3+ q3 = (p + q)(p2 + q2 – p q)
p3+ q3 + r3 – 3pqr = ?