Answer
$s^{9}t^{3}$
Work Step by Step
Using the laws of exponents, the given expression, $
(s^4t)^2(st)
,$ is equivalent to
\begin{align*}
&
\left( s^{4(2)}t^{1(2)}\right)(st)
&\text{ (use $(a^x)^y=a^{xy}$)}
\\&=
s^{8}t^{2}st
\\&=
s^{8+1}t^{2+1}
&\text{ (use $(a^x\cdot a^y=a^{x+y}$)}
\\&=
s^{9}t^{3}
.\end{align*}
Hence, the simplified form of the given expression is $
s^{9}t^{3}
$.
