Question

решите систему уравнения 2x - y =5 и x2 + y + 2 = 0

Answer 1

$left { {{2x - y = 5} atop {x^2 + y + 2 = 0}} right. \ \ left { {y = 2x - 5} atop {x^2 + y + 2 = 0}} right. \ \ left { {y = 2x - 5} atop {x^2 + 2x - 5 + 2 = 0}} right. \ \ left { {y = 2x - 5} atop {x^2 + 2x - 3= 0}} right.$
Решим второе квадратное уравнение:
$x^2 + 2x - 3 = 0 \ x_1 + x_2 = -2 \ x_1 cdot x_2 = -3 \ \ x_1 = -3 \ x_2 = 1$
$left { {{x = -3} atop {-6 - y = 5 }} right. left { {{x=1} atop {2 - y = 5}} right. \ left { {{x = -3} atop {y = -11}} right. left { {{x = 1 atop {y = -3 }} right.$
Ответ: $boxed{(-3; -11), (1; -3).}$