Determinati numarul natural necunoscut x, din fiecare inegalitate de mai jos

a) x </ 43-19
x </ 24
x apartine [0,24 ]
b) x >/ 28-11
x >/ 17
x apartine [ 17, +infinit)
c) x+20 < 83
x < 83-20
x < 63
x apartine (-1,63)
d) 2+x < 6
x < 6-2
x < 4
x apartine (-1, 4)