Răspuns:
Explicație pas cu pas:
f(x)=-3x/(x-2)
x.......................0................2..........
-3x +++++++++0------------------
x-2-------------------------------0 +++++
f ---------------0 +++++++I ---------
f≥0 pt x∈[0,2)
f<0 pt x∈(-∞,0)∪(2,∞)
b)
x...........................-5.............0...............2...................
x+5----------------0 +++++++++++++++++++++++
2-x++++++++++++++++++++++++++0 --------------
f -----------------0++++++++++++++I------------
f≥0 pt x∈[-5,2)
f<0 pt x ∈(-∞,-5)∪ (2,∞)
c)
x...................-5.........-2.......0...............5......................
x²-25.+++++++0------------------------------0++++++++++
x+2 -------------------------0+++++++++++++++++++++++++++++
f -------------0+++++ I-------------------0 +++++++++++++++++++
f≥0 pt x∈[-5,-2) ∪[5, ∞)
d)
x........................-4.........-3............................
-x-4+++++++++0 --------------------------
x+3-------------------------0+++++++++++++++++
f -----------------0+++++I --------------------------------
f≥0 pt x∈[-4,-3)
