Will give brainliest to whomever answers correctly !
factor completely 5x4 − 80.
a. 5(x^2 − 4)(x^2 + 4)
b. 5(x − 2)(x + 2)(x + 2)(x + 2)
c. 5(x − 2)(x + 2)(x^2 − 4)
d. 5(x − 2)(x + 2)(x^2 + 4)

Step-by-step explanation:

Since this is a 4th degree polynomial, 2 of the roots will not be real.  Finding them is next to impossible off a calculator until the real ones are found first.  That's  simple enough process.

and

Divide both sides by 5:

Rewrite to get

which simplifies down to

Taking the square root of both sides gives you the real roots of x = 2 and -2.

That leaves you with 2 roots that are imaginary.  After you factor out the 2 and the -2 by synthetic division, you are left with the depressed quadratic

 Factor out the 5:

So the final answer is D.