I want to alight enumerate my Exercises. My old way is

\begin{ex}
Find the volume of the following pyramids $ABCD$

\item $A(1; 2; 3)$, \quad $B(2; 1; -2)$, \quad $C(-1; -4; 3)$, \quad $D(2; 1; -5)$;

\item $A(1;-2;-4)$, \quad $B(-2;-1;0)$, \quad $C(3; 4;-2)$, \quad $D(5; 5; -5)$;

\item $A(3; 2; 1)$, \quad $B(2; 4; 6)$, \quad $C(1; 5; 3)$, \quad $D(5; 4; 3)$.

\end{enumerate}
\end{ex}


Now I want to align coordinates of the vertices A, B, C, D. I tried

\begin{ex}
Find the volume of the following pyramids

\setcounter{eqn}{0}
\begin{alignat*}{6}
\end{alignat*}
\end{ex}


How can I align to all vertices A, B, C, D to the left (none right with A and C like the second picture) and how can I add answer to every item like my old way?

My full code

\documentclass{article}
\usepackage{amsmath}
\newcounter{eqn}
\usepackage{enumerate}
\renewcommand*{\theeqn}{\arabic{eqn})}
\usepackage{amsthm}
\theoremstyle{definition}
\newtheorem{ex}{Exercise}
\begin{document}
\begin{ex}
Find the volume of the following pyramids $ABCD$
\item $A(1; 2; 3)$, \quad $B(2; 1; -2)$, \quad $C(-1; -4; 3)$, \quad $D(2; 1; -5)$;

\item $A(1;-2;-4)$, \quad $B(-2;-1;0)$, \quad $C(3; 4;-2)$, \quad $D(5; 5; -5)$;

\item $A(3; 2; 1)$, \quad $B(2; 4; 6)$, \quad $C(1; 5; 3)$, \quad $D(5; 4; 3)$.

\end{enumerate}
\end{ex}

\begin{ex}
Find the volume of the following pyramids
\setcounter{eqn}{0}
\begin{alignat*}{6}
\end{alignat*}
\end{ex}
\end{document}

• You want to align all A, B etc?
– user11232
Nov 28, 2014 at 4:02
• @HarishKumar Yes. I want to align all A, B Nov 28, 2014 at 7:12

Is it like this?

\documentclass{article}
\usepackage{amsmath}
\newcounter{eqn}
\usepackage{enumerate}
\renewcommand*{\theeqn}{\arabic{eqn})}
\usepackage{amsthm}
\theoremstyle{definition}
\newtheorem{ex}{Exercise}

\newcommand*{\mybox}[1]{%
\makebox[1in][l]{$#1$}
}
\begin{document}
\begin{ex}
Find the volume of the following pyramids $ABCD$
\item \mybox{A(1; 2; 3),} \mybox{B(2; 1; -2),} \mybox{C(-1; -4; 3),} \mybox{D(2; 1; -5);}

\item \mybox{A(1;-2;-4),} \mybox{B(-2;-1;0),} \mybox{C(3; 4;-2),} \mybox{D(5; 5; -5);}

\item \mybox{A(3; 2; 1),} \mybox{B(2; 4; 6),} \mybox{C(1; 5; 3),} \mybox{D(5; 4; 3).}

\end{enumerate}
\end{ex}

\begin{ex}
Find the volume of the following pyramids
\setcounter{eqn}{0}
\begin{alignat*}{6}

• Yes. Change it at \newcommand*{\mybox}[1]{% \makebox[1in][l]{$#1$} Nov 28, 2014 at 7:18