Find the 57th term of the arithmetic sequence minus, 13, comma, minus, 29, comma, minus, 45, comma, point, point, .−13,−29,−45,...
The common difference in this arithmetic sequence is $-16$. We can find the 57th term by starting with the first term, $-13$, and repeatedly adding $-16$. The $n$th term is $-13 + (-16)(n-1)$. Thus, the 57th term is \begin{align*}
-13 + (-16)(57-1) &= -13 + (-16)(56) \\
&= -13 + (-16)(4)(14) \\
&= -13 + (-64)(14) \\
&= -13 + (-896) \\
&= \boxed{-909}.
\end{align*}