tolong ya kak ini gimana bingung soalnya

9^3x - 2.3^3x+1 - 27 = 0
(3^3x)^2 - 2.3^3x.3 - 27 = 0
misal 3^3x = a
a² - 6a - 27 = 0
(a - 9)(a + 3) = 0
a = 9            a = -3
3^3x = 9       3^3x = -3 (?)
3^3x = 3²
3x = 2
x = 2/3
Hp = {2/3}