(i) (2p + 3q) (4p2 – 6pq + 9q2)
(ii) (x + 1/x) (x2 – 1 + 1/x2)
Answer :
(i) (2p + 3q) (4p2 – 6pq + 9q2)
It can be written as
= (2p + 3q) [(2p)2 – 2p × 3q + (3q)2]
By further simplification
= (2p)3 + (3q)3
= 8p3 + 27q3
(ii) (x + 1/x) (x2 – 1 + 1/x2)
It can be written as
= (x + 1/x) [x2 – x × 1/x + (1/x)2]
By further simplification
= x3 + (1/x)3
= x3 + 1/x3