Answer
$x=\dfrac{3}{4}$
Work Step by Step
$\log_{2}6-\log_{2}x=3$
Combine $\log_{2}6-\log_{2}x$ as the $\log$ of a division:
$\log_{2}\dfrac{6}{x}=3$
Rewrite this equation in exponential form:
$2^{3}=\dfrac{6}{x}$
$\dfrac{6}{x}=8$
Solve for $x$:
$\dfrac{x}{6}=\dfrac{1}{8}$
$x=\dfrac{6}{8}$
$x=\dfrac{3}{4}$