## College Algebra (6th Edition)

$log(xy^{3})$
According to the power rule of logarithms, we know that $log_{b}M^{p}=plog_{b}M$ (when $b$ and $M$ are positive real numbers, $b\ne1$, and $p$ is any real number). Therefore, $log(x)+3log(y)=log(x)+log(y^{3})$. Based on the product rule of logarithms, we know that $log_{b}(MN)=log_{b}M+log_{b}N$ (for $M\gt0$ and $N\gt0$). Therefore, $log(x)+log(y^{3})=log(xy^{3})$. In this case, the given logarithm is a common logarithm, which has an understood base of 10.