Ответ:
Объяснение:
[tex]\left \{ {{x^2+y^2=9} \atop {x+y=3}} \right. \\\left \{ {{x^2+y^2=9} \atop {x=3-y}} \right. \\\left \{ {{(3-y)^2+y^2=9} \atop {x+y=3}} \right. \\\left \{ {{9-6y+y^2+y^2=9} \atop {x+y=3}} \right. \\\left \{ {{-6y+2y^2=0} \atop {x+y=3}} \right. \\\\[/tex]
[tex]\left \{ {{y=0} \atop {x=3}} \right.[/tex] или [tex]\left \{ {{y=3/2} \atop {x=3/2}} \right[/tex]