X^8-81... i give best answers?

Question

factor...

i give best answers

Answer 1

x^8-81

Is a difference of squares because it can be rewritten as:

x^8-81 = (x^4)² - 9²

A Difference of squares (a²-b²) factors as (a+b)(a-b)

So...(x^4)² - 9² will factor as

(x^4+9)(x^4-9)

Now a sum of squares doesn't factor over the real numbers so x^4+9 won't factor any more, but x^4-9 is another difference of squares and can be rewritten as ((x²)² - 3²)

So this part factors as

((x²)² - 3²) =  (x²-3)(x²+3)

Since 3 is not a difference of squares (at least not over  whole numbers) I'm stopping here.

The answer would be:

(x^4 + 9)(x²+3)(x²-3)

Answer 2

srry?? i dont understand u

Answer 3

x^8-81

(x^4-9)(x^4+9)

(x^2-3)(x^2+3)(x^4+9)

(x+ sqrt 3)(x-sqrt 3)(x^2+3)(x^4+9)