\documentclass{article}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}

\begin{document}

\begin{align*}
1 + 1 &=& 2
\\1 &=& 2 - 1
\\0 &=& 2 - 1 - 1
\\0 &=& 2 - 2
\end{align*}

\end{document}