Xy = 6
2x - y = 11
xy = 6
y = 2x - 11
x(2x - 11) - 6 = 0
y = 2x - 11
2x² - 11x - 6 = 0
D = 121 + 4•2•6 = 169 = 13²
x1 = (11 + 13)/4 = 24/4 = 6
x2 = (11 - 13)/4 = -1/2
у = 2х - 11
x = 6
y = 1
x = 6
xy = 6
x = -1/2
y = -12
x = -1/2
Ответ: (6; 1), (-1/2; -12).