Question

помогите пожалуйста решить​

Answer 1

$+\left \{ {{x-2y=7} \atop {x+2y=-1}} \right.\\-------\\2x=6\\x=3\\2y=x-7=3-7=-4\\y=-2$

Ответ: (3 ; - 2)

Answer 2

$\left \{ {{x-2=7} \atop {x=2y=-1}} \right. \\\left \{ {{x=2} \atop {x+2y=-1}} \right. \\9+2y=-1\\y=-5\\(x,y)=(9,-5)\\\left \{ {{9-2=7} \atop {9+2*(-5)=-1}} \right. \\\left \{ {{7=7} \atop {-1=-1}} \right. \\(x,y)=(9,-5)$