Question

(x-1)·(y-1)=7
Aflați x și y

Answer 1

(x-1)(y-1)=7
7=7·1 sau 7=1·7
x-1=7⇒x=8; y-1=1⇒y=2;
x-1=1⇒x=2; y-1=7⇒y=8;
7=(-1)·(-7) sau 7=(-7)·(-1)
x-1=-1⇒x=0; y-1=-7⇒y=-6;
x-1=-7⇒x=-6; y-1=-1⇒y=0;
(x;y)∈{(8;2),(2;8),(0;-6),(-6;0)}