## Functions Modeling Change: A Preparation for Calculus, 5th Edition

$x \approx 0.783$
Take the natural log of both sides to get $$\ln 12^x = \ln 7$$ Since $\ln a^b=b \ln a$, the equation becomes $$x \ln 12 = \ln 7$$ Divide both sides by $\ln 12$ to get $$x=\frac{\ln 7}{\ln 12}\approx0.783$$