Решите систему уравнений а) 15x^2-2xy=5 и 2x-y=3

15x² - 2xy = 5

2x - y = 3

15x² - 2xy = 5

y = 2x - 3

15x² - 2x (2x - 3) - 5 = 0

y = 2x - 3

15x² - 4x² + 6x - 5 = 0

y = 2x - 3

11x² + 6x - 5 = 0

D = 36 + 5•11•4 = 256 = 16²

x1 = (-6 + 16) / 22 = 10/22 = 5/11

x2 = (-6 - 16) / 2 = - 22/22 = - 1

x = 5/11

y = 2•5/11 - 3

x = - 1

y = - 2 - 3

x = 5/11

y = - 23/11

x = - 1

y = - 5

Ответ: (5/11; - 23/11) ; (-1; - 5).