The polynomial equation x^3+x^2=-9x-9 has complex roots +/-3i what is the other root? use a graphing calculator and a system of equations.

  For this case what you can do is factorize the polynomial equation, which would be left like follows
 x ^ 3 + x ^ 2 + 9x + 9 = 0
 (x + 1) (x ^ 2 + 9) = 0
 Resolving, we have that the missing root is
 x = -1
 Answer
 x=-1