How do I solve polynomial equation by finding all complex roots?

Question

The problem is:
factor each expression and find all complex roots of x^3+64

I got as far as x^3+64=(x+4)(x^2-4x+16)
Now how do i find the roots of (x+4) and the roots of (x^2-4x+16)

Thanks

Answer 1

the root of x+4=0 is x=-2

the roots of the next can be solved by the quadratic equation..

x=(4+-sqrt(16-64))/2

that gives you three roots.

Answer 2

When a trinomial is factored as (x + m)(x + n), what is the sum of m and n?

A. The coefficient of the x-term of the trinomial
B. The constant term of the trinomial
C. The degree of the trinomial
D. The coefficient of the x2-term of the trinomial