college algebra
posted by allisonplease help!!! .
Solve the following inequality.
x^3+9x^2108 less or equal to 0.
Then write your solution in interval notation. I am sooo confused and do not have any idea how to do this. Can someone please show me step by step please???
Thanks in advance. Someone who is confused.

This polynomial graphing might help sometimes:
http://mathportal.org/calculators/polynomialssolvers/polynomialgraphingcalculator.php
zeros at x = 6 (double zero) and x = +3
so we really have
(x+6)(x+6)(x3)
It is negative for large negative x
it comes up and bounces off the x axis at x=6, dropping down negative again
it does not actually come up and cross the x axis until x = 3
from then on it is positive,
therefore negative for
x</= +3 except for touching zero at x = 6