Răspuns :
Răspuns:
7 fiind un nr prim are ca divizori:-1,-7,1,7=>2k+1 poate fi -1,-7,1,7
2k+1=1=>2k=1-1=>k=0
2k+1=7=>2k=7-1=>k=6:2=>k=3
2k+1=-1=.>2k=-1-1=>k=-1
2k+1=-7=>2k=-7-1=>k=-4
k = 0,3,-1,-4
Răspuns:
7 fiind un nr prim are ca divizori:-1,-7,1,7=>2k+1 poate fi -1,-7,1,7
2k+1=1=>2k=1-1=>k=0
2k+1=7=>2k=7-1=>k=6:2=>k=3
2k+1=-1=.>2k=-1-1=>k=-1
2k+1=-7=>2k=-7-1=>k=-4
k = 0,3,-1,-4