Algebra - Logarithmic Equations

Solve the equation: $\;$ $\log_2 \left(4 \times 3^x - 6\right) - \log_2 \left(9^x - 6\right) = 1$


Given equation: $\;\;$ $\log_2 \left(4 \times 3^x - 6\right) - \log_2 \left(9^x - 6\right) = 1$

i.e. $\;$ $\log_2 \left(\dfrac{4 \times 3^x - 6}{9^x - 6}\right) = 1$

i.e. $\;$ $\dfrac{4 \times 3^x - 6}{9^x - 6} = 2^1 = 2$

i.e. $\;$ $4 \times 3^x - 6 = 2 \times 9^x - 12$

i.e. $\;$ $2 \times 3^{2x} - 4 \times 3^x - 6 = 0$

i.e. $\;$ $\left(3^x\right)^2 - 2 \times 3^x - 3 = 0$

i.e. $\;$ $\left(3^x\right)^2 - 3 \times 3^x + 3^x - 3 = 0$

i.e. $\;$ $3^x \left(3^x - 3\right) + 1 \left(3^x - 3\right) = 0$

i.e. $\;$ $\left(3^x + 1\right) \left(3^x - 3\right) = 0$

i.e. $\;$ $3^x = -1$ $\;$ or $\;$ $3^x = 3$

i.e. $\;$ $x = \log_3 \left(-1\right)$ $\;$ or $\;$ $x = \log_3 3 = 1$

$\because \;$ logarithim of a negative number is not defined,

$\therefore \;$ $x = \log_3 \left(-1\right)$ $\;$ is not a valid solution.

$\therefore \;$ The solution to the given equation is $\;\;$ $x = \left\{1 \right\}$