Question

Решите систему управнения

Answer 1

$\left \{ {{-x+2y=7}|*3 \atop {3x+4y=-1}} \right.\\\\+\left \{ {{-3x+6y=21} \atop {3x+4y=-1}} \right. \\-------\\10y=20\\\\y=2\\\\x=2y-7=2*2-7=4-7=-3\\\\x=-3\\\\Otvet:\boxed{(-3;2)}$