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

Yes, $q(r)=-4\left(\frac{1}{3}\right)^r$
Another way to write $\frac{1}{3^r}$ is $\left(\frac{1^r}{3^r}\right)=\left(\frac{1}{3}\right)^r$. Therefore, the equation is equal to $$q(r)=-4\left(\frac{1}{3}\right)^r$$