Question

{у+х=0 {4х+у=6 додаванням СРОЧНО​

Answer 1

Ответ:

$\left \{ {{x + y = 0} \atop {y + 4x = 6} } \right. \\ \\ \left \{ {{x = - y} \atop {y - 4y = 6} } \right. \\ \\ \left \{ {{ - 3y = 6} \atop {x = - y} } \right. \\ \\ \left \{ {{y = - 2} \atop {x = 2} } \right.$

Ответ: (2; -2)