Btukfyl

I am trying to prepare a slide in latex for presentation but couln't. I am writing the following latex command but it failed to run due to errors:

documentclass{beamer}

title{Sample tittle}

subtitle{sample}

begin{document}

frame{

titlepage

}

frame{

frametitle{sample page 1}

[frac{-b}{a}]

}

frame{

frametitle{sample page 2}

framesubtitle{an example}

begin{itemize}

item 1

item 1

item 3

end{itemize}

}

frame{

frametitle{paragraph content}

this is a paragraph

}

end{document}.

Please help me to run.
Thank you in advance.

There is a ] which should be a ] after frac{-b}{a}. I would really use the frame as an environment, i.e.begin{frame}andend{frame}`.

documentclass{beamer}

title{Sample tittle}

subtitle{sample}

begin{document}

begin{frame}

titlepage

end{frame}



begin{frame}

frametitle{sample page 1}

[frac{-b}{a}]

end{frame}

begin{frame}

frametitle{sample page 2}

framesubtitle{an example}

begin{itemize}

item 1

item 1

item 3

end{itemize}

end{frame}



begin{frame}

frametitle{paragraph content}

this is a paragraph

end{frame}

end{document}