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\begin{document}
\homework{\#}{MM/DD}
% Question 1
\begin{exercise}
This problem has several parts:
	\begin{enumerate}[(a)]
	\item The first part.
	\item The second part. 
	\item The third part. 
	\end{enumerate}
\end{exercise}
% Question 2
\begin{exercise}
For each of the following below, determine which option is correct.
\begin{enumerate}[(i)]
\item 
        \begin{tabular}{p{3cm}p{3cm}p{3cm}p{3cm}}
        a) $2 \cdot 2= 4$ & b) $x^3= x \cdot x$ & c) $\sin x = \cos x$ & d) $\sin x^2= \sin^2 x$
        \end{tabular} 
        \item
        \begin{tabular}{p{3cm}p{3cm}p{3cm}p{3cm}}
        a) $2 \cdot 2= 4$ & b) $x^3= x \cdot x$ & c) $\sin x = \cos x$ & d) $\sin x^2= \sin^2 x$
        \end{tabular} 
\end{enumerate}
\end{exercise}
% Question 3
\begin{exercise}
Compute the following integral:
	\[
	\int e^{-x^2} \;dx
	\] \vspace{6mm}
	
Referencias ecuaciones se vuelve más sencillo al usar el comando 
\begin{verbatim}
\ref{eqn:Nombre de la etiqueta}
\end{verbatim}
Tal como se muestra aquí, [\ref{eqn:Reaction_A}] en [\ref{eqn:Reaction_B}]:
\begin{eqnarray*}
           x+y & = & \frac{2x}{y} \\
           y(x+y) & =  & 2x \\
           xy+y^2 & = & 2x
      \end{eqnarray*}
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\end{exercise}
\newpage
Otra forma de poder ubicar varios balances puede ser usando tablas.
\begin{table}[!hbt]
    \centering
    \begin{tabularx}{\columnwidth}{*{3}{W}}
    \textbf{Balance momentos}&\textbf{Balance fuerza x}&\textbf{Balance fuerza y}\\
     \begin{eqnarray}\label{eqn:Reaction_A}
           \nonumber x+y & = & \frac{2x}{y} \\ 
           y(x+y) & =  & 2x \\ \nonumber
           xy+y^2 & = & 2x 
      \end{eqnarray} &  \begin{eqnarray}\label{eqn:Reaction_B}
           x+y & = & \frac{2x}{y} \\
           y(x+y) & =  & 2x \\ 
           xy+y^2 & = & 2x 
      \end{eqnarray} & \begin{eqnarray}\label{eqn:Reaction_C}
           x+y & = & \frac{2x}{y} \\ 
           y(x+y) & =  & 2x \\ 
           xy+y^2 & = & 2x 
      \end{eqnarray}\\
    \end{tabularx}
    \label{tab:my_label}
\end{table}
\end{document}