Answer the following questions about the squares (a+b)2 and (a−b)2.
(i) State the identities for (a+b)2 and (a−b)2.
(ii) Explain, with suitable algebraic reasoning, why the sign of the middle term is different in the two identities.
(iii) Using these identities, simplify (5p−3q)2−(5p+3q)2 and describe the type of algebraic expression obtained as the final result.