Consider the special case of Identity (IV) with b = –a. What do you get? It is related to Identity (III).
Use a suitable identity to get each of the following products.
(1.1m - 0.41) (1.1m + 0.4)
Use a suitable identity to get each of the following products.
(6x - 7) (6x + 7)
∵ (6x - 7) (6x + 7) = (6x + 7) (6x - 7)
∴ Using the identity, (a + b) (a - b) = a2 - b2
We have
   (6x + 7) ( 6x - 7) = (6x)2 - (7)2
                                 Â
                            = 36x2 - 49