Answer
$\dfrac{4-3x}{8+x}$
Work Step by Step
The given expression, $
\dfrac{1-\dfrac{3x}{4}}{2+\dfrac{x}{4}}
,$ simplifies to
\begin{array}{l}\require{cancel}
\dfrac{\dfrac{4-3x}{4}}{\dfrac{8+x}{4}}
\\\\=
\dfrac{\dfrac{4-3x}{\cancel{4}}}{\dfrac{8+x}{\cancel{4}}}
\\\\=
\dfrac{4-3x}{8+x}
.\end{array}