To determine which company is the better choice to hire, tabulate the total cost that Carlos and Clarita will pay for a given number of windows to be cleaned.

\begin{tabular}{|c|c|c|c|c|}
\hline
\begin{tabular}{l}
Number of Windows, \\
[tex]$N$[/tex]
\end{tabular} & \multicolumn{2}{|c|}{\begin{tabular}{l}
Cost, [tex]$C$[/tex], for \\
Sunshine Express
\end{tabular}} & \multicolumn{2}{|c|}{\begin{tabular}{l}
Cost, [tex]$C$[/tex], for \\
"Pane"less
\end{tabular}} \\
\hline 0 & \multicolumn{2}{|c|}{50} & \multicolumn{2}{|c|}{25} \\
\hline 1 & \multicolumn{2}{|c|}{60} & \multicolumn{2}{|c|}{40} \\
\hline 2 & 70 & & 55 & \\
\hline 3 & 80 & & 70 & \\
\hline 4 & 90 & & 85 & \\
\hline[tex]$\ldots$[/tex] & \multicolumn{2}{|l|}{\ldots} & \multicolumn{2}{|l|}{\ldots} \\
\hline[tex]$N$[/tex] & \multicolumn{2}{|l|}{} & & \\
\hline
\end{tabular}