ada yang bisa jawab?

4^(log x) - 3.2^(1 + log x) + 8 = 0
misal:
2^log x = a
maka:
a² - 6a + 8 = 0
(a - 2)(a - 4) = 0
a = 2 ⇒ 2^log x = 2
maka log x = 1
x = 10
a = 4 ⇒ 2^log x = 2²
log x = 2
x = 100
Jawaban: E. 10 dan 100