Question

(x² - y² = 0,
4 + xy = 0;​

Answer 1

$\left \{ {{x^2-y^2=0} \atop {4+xy=0}} \right. =>\left \{ {{(x-y)(x+y)=0} \atop {4+xy=0}} \right. => \\\\x-y=0\\x+y=0\\x_1=y\\x_2=-y\\\\4+y*y=0\\4+y^2=0\\y^2=-4\\y \in \emptyset\\\\4-y*y=0\\4-y^2=0\\y^2=4\\y_{1,2}=\pm2\\\\x_{1,2}=\pm2$

ОТВЕТ: $x_{1,2}=\pm2\\y_{1,2}=\pm2$