Posted by Margaret on .
X^3+9x^2108¡Ý0

Math 
Steve,
If you mean to solve
x^3+9x^2108 <= 0
first find the factors:
(x+6)^2 (x3) <= 0
Now, (x+6)^2 >= 0 for all x, so we want
(x3) <= 0
x <= 3
Makes sense, since if you think of the graph, it comes up from lower left, touches the xaxis at x = 6, dips back down, and finally crosses into positive values at x=3.