Find the value of n if 3^2n+1 =4 (3^n+1) +9=0?

let x = 3^n

x^2 + 1 - (4 x + 4 + 9) = 0 ... x^2 - 4 x - 12 = 0

(x - 6) (x + 2) = 0 ... x = 6 , x = -2

3^n = 6 ... 3^n = -2 is an impossible solution

n log(3) = log(6)