设：a + 2√6 = b
1/a - 2√6 = c
(b - 2√6)(c + 2√6) = 1
bc + 2√6(b - c) = 25
由于都是整数,所以：2√6(b - c) = 0
b = c = ±5
a = ±5 - 2√6
方程a² - na + 1 = 0 没有实数解
n² - 4 < 0
-2 < n < 2
a² - na + 1 = 0
(a - n/2)² = (n² - 4)/4
a - n/2 = ±[√(n² - 4)]/2
a = ±[√(n² - 4)]/2 + n/2 = [n ±√(n² - 4)]/2