Chapter 12 - Section 12.8 - Exponential and Logarithmic Equations and Problem Solving - Exercise Set - Page 896: 16

{$13$}

$\log_{2} (x-5)=3$ $x-5=2^{3}$ $x-5=8$ $x=8+5=13$ Checking the answer by inserting it in the original equation: $\log_{2} (13-5)=3$ $\log_{2} (8)=3$ $\log_{2} 2^{3}=3$ $\log_{2} 2^{4}=4$ $3\log_{2} 2=3$ $3=3$ Therefore, the solution set is {$13$}.