Question 823061
Critical points are x at -4 and +1.
For the condition to be greater than zero, both factors are either positive or both factors negative.

x<-4?
(-)(-)=(+)>0.
Yes.


-4<x<1?
(+)(-)=(-)<0
No.


x>1?
(+)(+)=(+)>0
Yes.


Confirmed!