How do you solve x^4-81?

1 Answer
Dec 1, 2016

Resolve by factorization
(x+3)(x-3)(x^2+9)

Explanation:

Resolve by factorization considering a^2 - b^2 = (a+b)(a-b)
Detail is below
x^4-3^4 = (x^2)^2-(3^2)^2=(x^2-3^2)(x^2+3^2)=(x+3)(x-3)(x^2+9)