Factor (81x^4) - 336,960

Find the factors

81=3 times 3 times 3 times 3

336960=2 times 2 times 2 times 2 times 2 times 2 times 3 times 3 times 3 times 3 times 5 times 13

there is a 3 times 3 times 3 times 3 in both numbers (multiplied to get 81) so we divide both numbers by 81

81 ((x^4) - 4160)

that is the factored form