Question

Factor completely 625x8 − 1.

(25x4 − 1)(25x4 + 1)
(5x2 − 1)(5x2 + 1)(25x4 − 1)
(5x2 − 1)(5x2 + 1)(5x2 + 1)(5x2 + 1)
(5x2 − 1)(5x2 + 1)(25x4 + 1)

Answer 1

the answer is D, (5x2 − 1)(5x2 + 1)(25x4 + 1)

Explanation:

Answer 2

(5x^2 - 1)*(5x^2 + 1)*(25x^4 + 1)

Explanation:

Using a^2 - b^ 2 = (a-b)(a+b), factor the question into:

(25x^4 - 1)*(25x^4 + 1),

now further factor (25x^4 -1 ) using the same formula i.e [ a^2 - b^ 2 = (a-b)(a+b) ]

so we get our answer, that is:

(5x^2 - 1)*(5x^2 + 1)*(25x^4 + 1)