Answer
{$(-2,2),(2,2)$}
Work Step by Step
Two equations, we have $xy-4=0$ and $y=x$
From the second equation, we have
$x(x)-4=0$
or, $x^2=4$
Thus, $x=\pm 2$
From the second equation, we have
$y-(-2)=0$ (when x=-2)
or, $y=-2$
and
From the second equation, we have
$y-2=0$ (when x=2)
or, $y=2$
Hence, the solution set: {$(-2,2),(2,2)$}