Question

Detreminati multimea:
A={x apartine Z | x=2n+1/n+2} n aparine N

Answer 1

A={x∈ Z | x=2n+1/n+2} ;n ∈N
2n+1 trebuie sa fie divizibil cu n+2

si facem asa:
d divide  2n+1
d divide n+2 => d divide 2n+4
d divide 2n+4-2n-1 => d divide 3 => d∈{1,3}
Si avem :
n+2=3=> n=1 => 2n+1/n+2=2+1/1+2=3/3=1
n+2=1=> n=-1∉N
A={1}