For handy things in LaTeX
\vspace{0.6cm}
\hfill\begin{minipage}{\dimexpr\textwidth-2cm}
Hello!
\xdef\tpd{1cm}
\end{minipage}
\vspace{0.6cm}\documentclass{article}
\usepackage{amsmath}
\begin{document}
\[
f(x)=
\begin{cases}
\frac{x^2-x}{x},& \text{if } x\geq 1\\
0, & \text{otherwise}
\end{cases}
\]
\end{document}
$\xor$
Read here
\lstset{basicstyle = \ttfamily,columns=fullflexible}
\begin{lstlisting}[language={[x86masm]Assembler}]
push eax
\end{lstlisting}