3^2x + 2 . 3^(x+1) = 27 nilai x?

jawab

3²ˣ + 2. 3ˣ⁺¹ = 27
(3ˣ)² + 2. 3. (3ˣ) = 27

3ˣ= a

a² + 6a - 27=0
(a +9)(a - 3)= 0
a= -9   atau a = 3

(3ˣ)= 9 --> x= 2
(3ˣ)= 3 --> x = 1