{×^2+у^2=7 {3×^2-у^2=9

Question

{×^2+у^2=7
{3×^2-у^2=9

Answer 1

Складываем:
x^2+y^2+3x^2-y^2=7+9
4x^2=16
x^2=4
x1=2
x2=-2
y^2=7-x^2
y^2=7-4
y^2=3
y1=sqrt(3)
y2=-sqrt(3)
Ответ: (2;sqrt(3)), (-2;sqrt(3)), (-2;-sqrt(3)); (2;-sqrt(3))