(√24-√6)*√6 = √144 - 6 = 12-6 = 6
543
x + y = 10 (1)
x² - y² = 40 (2)
раскладываем (2)
(x - y)(x + y) = 10*(x - y) = 40
x - y = 4
складываем с (1)
2х = 14
х = 7
x + y = 10 y = 3
ответ (7,3)
547
x² - 3y = 22
x + y = 2
y = 2 - x
x² - 3(2 - x) = 22
x² - 6 + 3x - 22 = 0
x² + 3x - 28 = 0
D=9 + 112 = 121
x12 = (-3 +- 11)/2 = 4 -7
x1=4
x+y=2
y=-2
x2=-7
x+y = 2
y = 9
ответ (4, -2) (-7, 9)