Add slides on Red Hat and Arch Linux in 03-linux

03-linux/03-linux.tex

@@ -234,6 +234,44 @@ \section{Linux}
   \end{minipage}
 \end{frame}
 
+\begin{frame}{Red Hat Enterprise Linux}
+  \begin{minipage}[t]{0.65\textwidth}
+    Red Hat Enterprise Linux (RHEL):
+    \begin{itemize}
+      \item Commercial, enterprise-focused distribution by Red Hat (IBM)
+      \item Emphasis on stability, long-term support, certifications
+      \item Follows Fedora as upstream; ships well-tested packages
+      \item Common in servers, cloud, and regulated environments
+      \item Uses \texttt{dnf}/\texttt{yum} and SELinux by default
+    \end{itemize}
+  \end{minipage}
+  \hfill
+  \begin{minipage}[t]{0.3\textwidth}
+    \centering
+    \IfFileExists{images/redhat.png}{\includegraphics[width=0.9\textwidth]{images/redhat.png}}{\textbf{Red Hat}}
+    \\[6pt]
+    \IfFileExists{images/fedora.png}{\includegraphics[width=0.75\textwidth]{images/fedora.png}}{\textbf{Fedora}}
+  \end{minipage}
+\end{frame}
+
+\begin{frame}{Arch Linux}
+  \begin{minipage}[t]{0.65\textwidth}
+    Arch Linux:
+    \begin{itemize}
+      \item Rolling-release, minimalist, KISS philosophy
+      \item User-centric: manual setup, explicit configuration
+      \item Uses \texttt{pacman} and the Arch User Repository (AUR)
+      \item Fast access to latest software; requires proactive maintenance
+      \item Popular among advanced users and developers
+    \end{itemize}
+  \end{minipage}
+  \hfill
+  \begin{minipage}[t]{0.3\textwidth}
+    \centering
+    \IfFileExists{images/arch.png}{\includegraphics[width=0.8\textwidth]{images/arch.png}}{\textbf{Arch Linux}}
+  \end{minipage}
+\end{frame}
+
 \begin{frame}{Package managers}
   \begin{itemize}
     \item \texttt{APT (Advanced Package Tool)} for Debian-based systems.

03-linux/03-linux.toc

@@ -1,6 +1,6 @@
 \beamer@sectionintoc {1}{Introduction}{3}{0}{1}
 \beamer@sectionintoc {2}{History}{7}{0}{2}
 \beamer@sectionintoc {3}{Linux}{13}{0}{3}
-\beamer@sectionintoc {4}{Basic Linux commands}{18}{0}{4}
-\beamer@sectionintoc {5}{Connection to remote devices}{24}{0}{5}
-\beamer@sectionintoc {6}{Running Linux}{28}{0}{6}
+\beamer@sectionintoc {4}{Basic Linux commands}{20}{0}{4}
+\beamer@sectionintoc {5}{Connection to remote devices}{26}{0}{5}
+\beamer@sectionintoc {6}{Running Linux}{30}{0}{6}