Question

Determinati perechile de numere intregi (x,y) pentru care: xy + x - 2y=7

Answer 1

xy+x-2y=5+2
xy-2y+x-2=5
y(x-2)+(x-2)=5
(x-2)(y+1)=5=(-1)x(-5)=(-5)x(-1)=1x5=5x1
x-2=-1, x=1, y+1=-5, y=-6
x-2=-5, x=-3, y+1=-1, y=-2
x-2=1, x=3, y+1=5, y=4
x-2=5, x=7, y+1=1, y=0