Question

Determina elementele multimii A = {n apartine N | 3n+27 supra n + 2 apartine N} VA ROOG MULT DAU COROANA!!!!

Answer 1

(3n+27)/(n + 2) apartine N
=>   n+2|3n+27
dar  n+2|3n+6  (-)   ;n+2|3(n+2) si n+2 divide si diferenta nr pe care le divide
..............................
=>  n+2|21
n+2={3,7,21}

deci n={1,5,19}