Question 983908
Possible roots to try are PLUS AND MINUS OF 1,3,9,27.


Use synthetic division to test.


<pre>
-1    |    1    -2    6    -18    -27
      |         -1    3    -9      27
      |___________________________________
           1    -3    9    -27     0


-1    |    1    -3    9    -27
      |         -1    4    -13
      |___________________________________
           1    -4    13    -40



-3    |    1    -3    9    -27
      |         -3   18    -81
      |___________________________________
           1    -6   27    -108


1     |     1    -3    9    -27
      |           1    -2    7
      |___________________________
            1    -2    7     -20


3      |     1    -3    9    -27
       |           3    0     27
       |__________________________
             1     0    9     0
</pre>


So far, two roots and the quadratic binomial:
{{{highlight_green((x+1)(x-3)(x^2+9))}}}.


The last two roots are imaginary,  {{{x=-i*sqrt(3)}}} and {{{x=i*sqrt(3)}}}.