Answer
$log_{6}(15x+60)$
Work Step by Step
We know that $log_{b}xy=log_{b}x+log_{b}y$ (where $x$, $y$, and $b$ are positive real numbers and $b\ne1$).
Therefore, $log_{6}3+log_{6}(x+4)+log_{6}5=log_{6}(3\times5\times(x+4))=log_{6}(15\times(x+4))=log_{6}(15x+60)$.
