Tolong yapake cara nyacuman nomor 3 lg

4ˣ – 9(2ˣ) + 8 = 0
2²ˣ – 9(2ˣ) + 8 = 0

misal  2ˣ = a
a² – 9a + 8 = 0
(a – 8)(a – 1) = 0
a = 8
2ˣ = 8
2ˣ = 2³
x = 3

a = 1
2ˣ = 1
2ˣ = 2⁰
x = 0

maka x = 0 atau x = 3