Question 901151
The roots are the critical x values.


Check in the intervals of x, {{{-infinity<x<-9}}}, {{{-9<x<2}}}, and {{{2<x<infinity}}}.


Recognize that f(x) is a parabola with positive coefficient on {{{x^2}}}.  f will be positive for {{{x<-9}}} and for {{{x>2}}}.