\documentclass[a4paper,12pt]{article}
\usepackage{epsfig}
\newcommand{\un}{\underline}
\newcommand{\ds}{\displaystyle}
\begin{document}
\parindent=0pt

\begin{center}
\textbf{Ordinary Differential Equations}

\textit{\textbf{Classification}}
\end{center}

\textbf{Question}

For the following differential equation, give its order, and whether
it is linear or non-linear. If it is linear, state whether it is
homogenous or nonhomogenous.

$\ds y\frac{dy}{dx} = x$


\textbf{Answer}

Non-linear, 1st order.

\end{document}