Diketahui 9^x-2 = (1/3)^x²-4x+1 maka nilai 3x adalah...

3^2(x-2) = 3^(-1)(x²-4x+1)
2x - 2 = -x² + 4x - 1
x² - 2x -1 = 0
(x-1)(x-1) = 0
x = 1

3x = 3*1 = 3