Which of the binomials below is a factor of this trinomial x8-8x-48?

Answer 1

If, perhaps, you meant x^2 - 8x - 48, then the factors are (x - 12) & (x + 4).

If you really meant x^8 - 8x - 48, then there are 2 real factors at (x+1.562) & (x-1.673) [Approximate, using numerical means], the other 6 should be complex number factors.

Answer 2

(x - 1)^8 + 8(x - 1)^7 + 28(x - 1)^6 + 56(x - 1)^5 + 70(x - 1)^4 + 56(x - 1)^3 + 28(x - 1)^2 - 55