Fie x = 1 => (3*1+1)(y+2)=48 => 4(y+2)=48|:4 => y+2=12=>y=12-2=10.
Avem perechea (1,10).
Fie x = 5 => (3*5+1)(y+2)=48=>16(y+2)=48|:16 => y+2 = 3 => y = 3-2=1.
Avem perechea (5,1).
=> (x,y) = {(1,10),(5,1)}.
Daca incerci si celelalte cazuri, vei observa ca perechile nu vor fi naturale.
Succes!