solve x^4-8x^3+64x-105=0 given that 2-i is one solution.

Question

must be tired cause my steps are not calculating correctly

Answer 1

what you should do is show how far you got, if you want help.

another root is necessarily 2+i, so

(x^2-4x+5) divides x^4-8x^3+64x-105

In fact,

x^4-8x^3+64x-105 = (x^2-4x+5)(x^2-4x-21)
Now it's a piece o' cake, no?