3ˣ = a
1 + 14/(a-9) + 48/(a² - 18a + 81) ≥ 0
(a² - 18a + 81 + 14(a-9) + 48) / (a-9)² ≥ 0
(a² - 18a + 81 + 14a - 126 + 48) / (a-9)² ≥ 0
(a² - 4a + 3) / (a-9)² ≥ 0
(a - 1)(a - 3)/(a - 9)² ≥ 0
_+___[1]__-__[3]__+___(9)___+____
1)
3ˣ ≤ 1
x ≤ 0
2) 3 ≤ 3ˣ < 9
1 ≤ x < 2
3) 3ˣ > 9
x > 2
Ответ: (-∞; 0] U [1; 2) U (2; +∞)