Question

Помогите пожалуйста решить. ​

Answer 1

Ответ:

(4,5;-12,5)

Объяснение:

$\left \{ {{x+y=-8} \atop {x-y=17}} \right. \\\\\left \{ {{x=-8-y} \atop {(-8-y)-y=17}} \right. \\ \\ \left \{ {{x=-8-y} \atop {-8-y-y=17}} \right. \\ \\ \left \{ {{x=-8-y} \atop {-2y=25 |:(-2)}} \right.\\ \\ \left \{ {{x=-8-y} \atop {y=-12.5}} \right.\\\\ \left \{ {{x=4,5} \atop {y=-12.5}} \right.$