Question

$\left \{ {{x+y=3} \atop {2x+y-5}} \right.$

Answer 1

$x + y = 3 \\ 2x + y = - 5 \\ \\ x = 3 - y \\ 2x + y = - 5 \\ \\ 2(3 - y) + y = - 5 \\ y = 11 \\ \\ 2x + 11 = - 5 \\ x = - 8$