Factorization by identity a2- b2

1. Factorize the following expression by using an identity. p2 – 9 Tip : 9 = 3² So, p2 – 9 = p² - 3² a2 - b2 = (a + b)(a - b) So, a = p and b = 3. Factorizing p2 – 9 using a2 - b2 = (a + b)(a - b) identity we get ∴ p2 – 9 = (p + 3) (p - 3) Substituting a = p and b = 3 in (a + b)(a - b)

2. Factorize the following expression by using an identity. 4p2 – 49 Tip : 4 = 2² and 49 = 7² So, 4p2 – 49 = 22p² - 7² = (2p)2- 7² a2 -b2 = (a + b)(a - b) So, a = 2p and b = 7. Factorizing 4p2 – 49 using a2 - b2 = (a + b)(a - b) identity we get ∴ 4p2 – 49 = (2p + 7) (2p - 7) Substituting a = p and b = 3 in (a + b)(a - b)

Try These Factorize the following expression by using identities :