Answer
$\dfrac{3-2\sqrt{7}}{4}$
Work Step by Step
Factoring the $GCF=4$ and then cancelling the common factor between the numerator and the denominator, the given expression, $
\dfrac{12-8\sqrt{7}}{16}
,$ simplifies to
\begin{array}{l}\require{cancel}
\dfrac{4(3-2\sqrt{7})}{16}
\\\\=
\dfrac{\cancel{4}(3-2\sqrt{7})}{\cancel{4}\cdot4}
\\\\=
\dfrac{3-2\sqrt{7}}{4}
.\end{array}
