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)

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

Step-by-step 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)

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