Question

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

Answer 1

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