Question

Очень срочно... 9 клас

Answer 1

у=2, х=4 або у=-2 ,х=-4.

Answer 2

$\left \{ {{2x^{2}-xy+y^{2}=28} \atop {x^{2}-4xy+4y^{2}=0}} \right.\\\\\left \{ {{2x^{2}-xy+y^{2}=28} \atop {(x-2y)^{2}=0 }} \right. \\\\\left \{ {{2x^{2}-xy+y^{2}=28} \atop {x-2y=0}} \right.\\\\\left \{ {{x=2y} \atop {2\cdot(2y)^{2}-y\cdot2y+y^{2}=28}} \right.\\\\\left \{ {{x=2y} \atop {8y^{2}-2y^{2}+y^{2}=28}} \right. \\\\\left \{ {{x=2y} \atop {7y^{2}=28 }} \right. \\\\\left \{ {{x=2y} \atop {y^{2}=4 }} \right.$

$\left \{ {{x=2y} \atop {\left[\begin{array}{ccc}y_{1}=-2 \\y_{2}=2 \end{array}\right }} \right.\\\\\\\left \{ {{\left[\begin{array}{ccc}x_{1} =-4\\y_{1}=-2 \end{array}\right } \atop {\left[\begin{array}{ccc}x_{2}=4 \\y_{2}=2 \end{array}\right }} \right.\\\\\\Otvet:\boxed{(-4 \ ; \ -2),(4 \ ; \ 2)}$