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.
(2y + 5) (2y + 5)
Using the identity
(x + a) (x + b) = x2 + (a + b)x + ab
We have
(2y + 5 ) (2y + 5) = (2y)2 + ( 5 + 5)2y + ( 5 x 5)
= (2y)2 + (10)2y + 25
= 4y2 + 20y + 25
Use a suitable identity to get each of the following products.
(1.1m - 0.41) (1.1m + 0.4)