Question

Determinati multimea A={x€Z | 2x-1/x+1 €Z}
"€"-apartine
"/'"-linie de fractie

Answer 1

(2x-1)/(x+1)=[(2x+2)-2-1]/(x+1)=2-3/(x+1)
trebuiesc determinati divizorii lui 3
D3={-3,-1,1,3}
x+1=-3 ,x=-4
x+1=-1 ,x=-2
x+1=1 ,x=0
x+1=3 ,x=2
x={-4,-2,0,2}