Răspuns:
Explicație pas cu pas:
e) (2x+1)(3-x)>0 x²+4>0 oricare ar fi x deci nu va conta la semnul expresiei
x..........................-1/2...................................3.............
2x+1 ----------------0+++++++++++++++++++++++++++
3-x+++++++++++++++++++++++++++++0---------------
f(x)-------------------0++++++++++++++++0----------------
x∈(-1/2,3)
f) x²-x-2=(x+1)(x-2)
x......................-1.........0..................2................
x+1--------------0+++++++++++++++++++++++++
x-2--------------------------------------0++++++++++++++
x---------------------------0+++++++++++++++++++++++++
f(x)--------------0+++++I--------------0++++++++++++++++
x∈(-∞,-1]∪(0,2]
