: ++++++++++++++++++++ (Sempre +)
: --------------[-2]+++++++
--------------------------[-2]+++++++
S(1) = x
-2
-2: -------------------------------- (Sempre negativo)
(x+4) -------(-4)+++++++++++++
(x-3)--------------------(3)+++++
--------------(-4)+++++(3)--------
S(2) = x < -4 ou x > 3
_______________[-2]++++++++++++++++
_________(-4)+++++++++(3)___________
_________(-4)
S(1)
S(2) = x < - 4