Question

х+у=3
х^2-у^2=-3
(х^2....это в квадрате)

Answer 1

$left { {{x+y=3} atop {x^2-y^2=-3}} right. \ x=3-y \ (3-y)^2-y^2=-3 \ 9-6y+y^2-y^2=-3 \ -6y=-12 \ y=2 \ x=3-2=1$
Ответ: (1; 2)