## College Algebra (11th Edition)

$-1$
$\bf{\text{Solution Outline:}}$ Use the properties of logarithms to simplify the given expression, $\log 0.1 .$ $\bf{\text{Solution Details:}}$ The given expression is equivalent to \begin{array}{l}\require{cancel} \log \dfrac{1}{10} .\end{array} Using the Quotient Rule of Logarithms, which is given by $\log_b \dfrac{x}{y}=\log_bx-\log_by,$ the expression above is equivalent \begin{array}{l}\require{cancel} \log 1-\log 10 .\end{array} Since $\log_b1=0$ and $\log_b b=1,$ the expression above is equivalent \begin{array}{l}\require{cancel} \log 1-\log_{10} 10 \\\\= 0-1 \\\\= -1 .\end{array}