\documentclass[12pt]{article}
\thispagestyle{empty}
\usepackage{hyperref}
\usepackage{amsmath}
\begin{document}
\huge{
$x^2 + 2 x (b/(2 a)) + (b/(2 a))^2 = (x + (b/(2 a)))^2$
}
\end{document}
