Question

determinati numarul natural x ,stiind ca:
x-3≤5
2+x≥5
x:4≥3

Answer 1

x-3≤5⇔x≤8⇒x∈ {0,1,2,...,8}
2+x≥5⇔x≥3⇒x∈ {3,4,5,...}
x:4≥3⇔x≥12⇒x∈{12,13,...}
daca x trebuie sa indeplineasca simultan conditiile, se calculeaza intersectia multimilor din care rezulta ca x∈Ф

Answer 2

x<=8   x= {0,1,2,3,4,5,6,7,8}
x>=3  x={3,4,5....}
x>=12  x={12,13,14...}