Answer
$(-2,-2)$, $(2,2)$
Work Step by Step
Re-arrange the given two equations and then use the substitution method to get
$y-x=0 \implies y=x$
Now, $x(x)-4 =0$
This gives: $x^2=4 \implies x=2,-2$
when $x=2$ then we have $y =2$
when $x=-2$ then we have $y =-2$
Hence, our answers are: $(-2,-2)$, $(2,2)$