Question

xy-x-y = 2

ai làm đc mik tik nhé

Answer 1

xy-x-y=2

x(y-1)-y=2

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

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

(y-1)(x-1)=1=1.1=(-1).(-1)

+) \(\left\{{}\begin{matrix}y-1=1\\x-1=1\end{matrix}\right.\)⇒ \(\left\{{}\begin{matrix}y=1+1\\x=1+1\end{matrix}\right.\)⇒ \(\left\{{}\begin{matrix}y=2\\x=2\end{matrix}\right.\)

+) \(\left\{{}\begin{matrix}y-1=-1\\x-1=-1\end{matrix}\right.\)⇒ \(\left\{{}\begin{matrix}y=\left(-1\right)+1\\x=\left(-1\right)+1\end{matrix}\right.\)⇒ \(\left\{{}\begin{matrix}y=0\\x=0\end{matrix}\right.\)

Vậy \(\left(x;y\right)=\left(2;2\right);\left(0;0\right)\)