## Intermediate Algebra (6th Edition)

Because $log_{b}1=0$
We are given that $log_{b}7=log_{b}(\frac{7}{1})=log_{b}7-log_{b}1$. Although this seems counterintuitive, we know that $log_{b}7=log_{b}7-log_{b}1$, because $log_{b}1=0$ according to the properties of logarithms. Therefore, $log_{b}7=log_{b}7-log_{b}1=log_{b}7-0=log_{b}7$.