Question

Решите систему управления
5x+y=7
7x-4y=-1

Answer 1

$\left \{ {{5x+y=7} \atop {7x-4y=-1}} \right. \left \{ {{y=7-5x} \atop {7x-4(7-5x)=-1}} \right. \left \{ {{y=7-5x} \atop {7x-28+20x=-1}} \right. \left \{ {{y=7-5x} \atop {27x=27}} \right. \left \{ {{y=2} \atop {x=1}} \right. (1;2)$