#### Answer

$3,458$

#### Work Step by Step

Substituting $s=4$ and $t=8$, the given expression, $
\dfrac{(3s)^3t+t}{s}
,$ evaluates to
\begin{array}{l}\require{cancel}
\dfrac{(3\cdot4)^3(8)+8}{4}
\\\\=
\dfrac{(12)^3(8)+8}{4}
\\\\=
\dfrac{(1728)(8)+8}{4}
\\\\=
\dfrac{13824+8}{4}
\\\\=
\dfrac{13832}{4}
\\\\=
3,458
.\end{array}