align with equal sign centered [duplicate]

Question

Possible Duplicate:
Align to center

I want to align some equations to the equal signs, so I wrote this:

\begin{align}
            -3z &= -9\\ 
              z &=  3\\
        -3y-3*3 &=  3\\ 
              y &= -4\\
  2x+8*(-4)+4*3 &=  2\\ 
              x &= 11
\end{align}

However, because one equation is much longer than the others, all the equations appear somewhat at the right of the page.

How can I make the equal signs appear in the middle of the page, while still aligning all the equations to them?

Answer 1

One possibility is to make the long expression occupy no space:

\begin{align}
            -3z &= -9\\ 
              z &=  3\\
        -3y-3*3 &=  3\\ 
              y &= -4\\
  \makebox[0pt][r]{$\displaystyle 2x+8*(-4)+4*3$} &=  2\\ 
              x &= 11
\end{align}