Can u solve this?

Question

Givin -1i is a root of this polynomial P(x)= x^3+7x^2+x+7 find the remaining roots and write in factored form

Answer 1

0 = x^3 + 7x^2 + x + 7 =

x^2(x+7) + x+7 =

x^2(x+7) + 1*(x+7) =

(x+7)(x^2 + 1) =

so then x+7 = 0 OR x^2 +1 = 0

x = -7 OR x^2 = -1

x = +or- i