Determina perechile de Nr naturale (x,y) pentru care 2*x*y+2*y=8

Răspuns :

2×X×Y + 2×Y = 8
2×Y × (X + 1) = 8 |:2
Y × ( X + 1) = 4
Y = 4/(X+1)
ptr X = 1 ==> Y = 4/2 = 2
ptr X = 3 ==> Y = 4/4 = 1

(X;Y) = (1;2) si (3;1)