2x + y - 11 = 0 => 2x + y = 11
2x + 5y - y^2 - 6 = 0 => 2x + y + 4y - y^2 - 6 = 0 => 11 + 4y - y^2 - 6 = 0 => - y^2 + 4y + 5 = 0 => y^2 - 4y -5 = 0 => y1*y2 = -5, y1 + y2 = 4 => y1 = 5, y2 = -1. Тогда 2x1 + 5 - 11 = 0 => 2x1 = 6 => x1 = 3 и 2x2 -1 -11 = 0 => 2x2 = 12 => x2 = 6.
Ответ: (x1, y1) = (3, 5), (x2, y2) = (6, -1).