Question 851880
factors to {{{(x-3)*(x+6)^2}}}

so we check the intervals

[-oo, -6] 
(+)(-)  so negative except at x=-6

[-6, 3]
(-)(+) so negative except at x=-6 and x=3


[3,oo]
(+)(+) positive


solution:

{-6} U [3, oo)