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Determinati numerele intregi x si y stiind ca 2x+xy-y=3 !!!

Răspuns :

Se observa ca
(x-1)(y+2)=xy+2x-y-2
ceeace inseamna c a

2x+xy-y=(x-1)(y+2)+2

expresia devine
(x-1)(y+2)+2=3
sau
(x-1)(y+2)=1
adica
(x-1)(y+2)=1*1 =(-1)*(-1)

avem cazurile
x-1=1 ...x=2
y+2=1....y=-1


x-1=-1  x=0
y+2=-1 y=-3

deci (x,y) ∈{(2;-1);(0;-3}