[texhax] \hline in align environment

[Sebastian Canagaratna]

Thank you for your suggestion. There are, in fact, only two columns, and
I was using three. It is interesting that all solutions that have been
suggested are not latex solutions, since \phantom, \multispan, \rlap etc
are used in tex, but not usually in latex. The closest I could come
toward a purely latex solution was this: 

\begin {align*}
      4x+  6y -2z &= -4\\
       x -y +2z   &=  9\\[-0.15in]
       \makebox[.8in]{\hrulefill}&\makebox[0.4in]{\hrulefill}\\
     5x + 5y    &= 5\\
        x + y &= 1
 \end {align*}

The disadvantage with this is that  one has to experimentally determine
the lengths.

Sebastian Canagaratna
Department of Chemistry and Biochemistry
Ohio Northern University
Ada, OH 45810