Question

a^4-81 factorize fast pls​

Answer 1

❍ Solution :-

$\sf →{a}^{4} - 81$

⇝ a⁴ = (a²)² and 81 = 9²

$\sf →{({a}^{2})}^{2} - {9}^{2}$

⇝ Square is common

$\sf →{({a}^{2} - 9)}^{2}$

Hence,

$\sf →({a}^{2} - 9)({a}^{2} - 9)$

Hence, (a² - 9)² or (a² - 9)(a² - 9) is the factorize form of a⁴ - 81.