Question

Решите систему уравнений методом сложения: { 2 x + 7 y = − 37 2 x − y = 3

Answer 1

$\left \{ {{2x+7y=-37|*(-1)} \atop {2x-y=3}} \right. \Longrightarrow \left \{ {{-2x-7y=37} \atop {2x-y=3}} \right. \\\\\\\\+\left \{ {{-2x-7y=37} \atop {2x-y=3}} \right. \\---------\\-8y=40\\y=-5\\\\2x-(-5)=3\\2x+5=3\\2x=-2\\x=-1$

Ответ: х=-1; у=-5