Question

simplify (a+3) (a-3) (a2+9)​

Answer 1

Step-by-step explanation:

(a+3)(a-3)(a²+9)

(a²-9)(a²+9) [identity used: (a-b)(a+b)=(a²-b²)]

a⁴-81

Answer 2

$\bold{\boxed{Answer:a⁴ - 81}}$

____________

(a+3) (a-3) (a²+9)

={ (a+3) (a-3)} (a²+3²)

= (a²-3²)(a²+3²)

= (a²)²- (3²)²

= a⁴ - 3⁴

= a⁴ - 81. ✓