Question

х+у=-2 . х^2-2ху+у^2=16

Answer 1

{х+у= -2
{х² - 2ху +у²=16

{x= -2 - y
{(-2-y)² - 2y(-2-y)+y²=16

4+4y+y² + 4y +2y² + y² = 16

4y²+8y-12=0 |: 4

y²+2y-3=0
D= 4+12= 16
y₁= -2+4/2= 1
у₂= -2-4/2= -3

х₁= -3
х₂= 1

Ответ:(-3;1) и (1;-3).