Write greek in latex for ubuntu

Question

I'm totally new in ubuntu. I want to write mathematical papers in greek in latex.

From the synaptic package manager I downloaded texlive and texstudio. Everything works fine in english, but i can't write in greek.

I wrote the following code.

\documentclass{article}
\usepackage[english,greek]{babel}
\usepackage{[iso-8859-7]{inputenc}
\begin{document}
ααα
\end{document}
\enddocumentclass{article}

And texstudio returned

''file babel.sty , unknown option greek...''

I tried that

\documentclass{article}
\usepackage[iso-8859-7]{inputenc}
\begin{document}
ααα
\end{document}
\enddocumentclass{article}

And it returned

''inputenc.sty :file iso-8859-7.def not found ''

Please tell me what to do to fix this problem.

If it's easy, give me some straight instructions if I have to use the terminal.

Answer 1

A quick search to see which package provides iso-8859-7.def turns up texlive-lang-greek. Therefore installing it might solve the problem:

sudo apt-get install texlive-lang-greek