Răspuns :
5|3x+y⇒5|2* (3x+y) adica
5|6x+2y
dar
5|5y
atuinci , adunand in dreapta, cf. propietatilor divizibilitatii ,
5|6x+2y+5y , adica
5|6x+7y, C.C.T.D.
5|3x+y: 5|3(3x+y); 5|9x+3y
5|15x+10y
Facem diferenta si obtinem
5|(15x+10y)-(9x+3y)
5|15x+10y-9x-3y
5|6x+7y
5|15x+10y
Facem diferenta si obtinem
5|(15x+10y)-(9x+3y)
5|15x+10y-9x-3y
5|6x+7y