Answer
$log_{7}5$
Work Step by Step
The quotient property of logarithms tells us that $log_{b}\frac{x}{y}=log_{b}x-log_{b}y$ (where x, y, and, b are positive real numbers and $b\ne1$).
Therefore, $log_{7}20-log_{7}4= log_{7}\frac{20}{4}=log_{7}5$.
