Question

(X + 1) | (2x + 5)
X€ N

Answer 1

Explicație pas cu pas:

x+1|2x+5

x+1|x+1 => x+1|2x+2

=>

x+1|2x+5-2x-2 => x+1|3 => x+1€D3 in N =>

x+1€{1,3} => x€{0,2}

Daca aveam x-1 atunci luam divizorii in Z dar cum ne cere x€N si avem x+1 e suficient cei naturali