Question

Решите систему уравнений :{х-4у=7{2х-у=7

Answer 1

$\left \{ {{x-4y=7} \atop {2x-y=7}} \right. \left \{ {{x-4y=7} \atop {-8x+4y=-28}} \right. \left \{ {{x-4y=7} \atop {-8x+4y=-28}} \right. -7x=-21, x=3, \left \{ {-4{y=7-3} \atop {x=3}} \right. \left \{ {{y=-1} \atop {x=3}} \right.$

Ответ: (3;-1)