Question

Rezolvati in multimea numerelor naturale : (250-x)-130>sau = 70 si x+50>sau = 70

Answer 1

250-X-130≥70
250-130-70≥X
X≤50  X∈{X∈N si X≤50}
X+50≥70
X≥70-50
X≥20   X∈{X∈N si X≥20}