I want to delete the line above x3 and x4. Can anyone help me? So the line on the left side stops above x3 and below x4.

[![enter image description here](https://i.stack.imgur.com/gqXpe.png)](https://i.stack.imgur.com/gqXpe.png)

The Tex is:

```
\begin{table}[htbp]
\setlength\extrarowheight{2pt} % for a more open "look"
\centering
\begin{tabular}{|C|CC|CC|C|C|}
%\cline{2-5}
%&  \multicolumn{2}{c|}{Nichtbasisvariable} 
%&   \multicolumn{2}{c|}{Basisvariable} \\
\cline{2-7}
& x_1 & x_2 & x_3 & x_4 & F & b_i \\
\hline

x_3 & 1 & 6 & 1 & 0 & 0 & 180 \\

x_4 & 3 & 1 & 0  & 1 & 0 & 90 \\
\hline
& -2 & -4 & 0 & 0 & 1 & 0 \\
\cline{2-7}
\end{tabular}
\caption{Übertragung des Beispiels \ref{bsp5} in das Simplextableau aus Definition \ref{def6} }
\label{tab2}
\end{table}

```