# How do you solve ln x + ln 3x = 12?

Dec 6, 2015

$x = + \frac{\sqrt{3}}{3} {e}^{6}$

#### Explanation:

$\ln \left(x \cdot 3 x\right) = 12$

$x \cdot 3 x = {e}^{12}$

${x}^{2} = \frac{1}{3} {e}^{12}$

x = ± sqrt(3)/3 e^6

But x > 0.