Răspuns :
3/(2x+1)∈Z=>(2x+1)∈D₃
D₃={±3;±1)
2x+1=-3=>2x=-4=>x=-2
2x+1=-1=>2x=-2=>x=-1
2x+1=1=>2x=0=>x=0
2x+1=3=>2x=2=>x=1
x∈{-2,-1,0,1}
3/(2x+1)∈Z=>(2x+1)∈D₃
D₃={±3;±1)
2x+1=-3=>2x=-4=>x=-2
2x+1=-1=>2x=-2=>x=-1
2x+1=1=>2x=0=>x=0
2x+1=3=>2x=2=>x=1
x∈{-2,-1,0,1}