Question

х+4у=7 x-2y = -5 дам 40 баллов

Answer 1

$\left \{ {{x+4y=7} \atop {x-2y=-5}} \right. \\\\ x = 2y-5\\ 2y-5+4y = 7\\ 6y = 12\\ y = 2\\ x = 2y-5 = -1$