√x + √y = 4
x + y - 3√(xy) = 1
x + y + 2√(xy) = 16
x + y - 3√(xy) = 1
5√(xy) = 15
√(xy) = 3
xy = 9
√x + √y = 4
√x = 3/√y
3/√y + √y = 4
y - 4√y + 3 = 0
D = 16 - 12 = 4
√y = (4 - 2)/2 = 1 => √x = 3/1 = 3
y = 1; x = 9
√y = (4 + 2)/2 = 3 => √x = 3/3 = 1
y = 9; x = 1
Ответ: (1; 9) и (9; 1)