Question

1) Find the product using suitable identity.
(a + 3) (a - 3) (a2 + 9)​

Answer 1

Answer:

a⁴ - 81

Step-by-step explanation:

Using (a + b)(a - b) = a² - b²

Here,

⇒ (a + 3)(a - 3)(a² + 9)

⇒ (a² - 3²)(a² + 9)

⇒ (a² - 9)(a² + 9)

⇒ (a²)² - (9)²

⇒ a⁴ - 81

Answer 2

Answer:

a=3

Step-by-step explanation:

a²-3a+3a-9 (a²+9)

(a²-9) (a²+9)

(a2)²-(9)²

a⁴+81

a⁴=-81

a=3