For simplicity, you can write the bounded variable as two additional constraints. In the following example, there are four positive variables with a bounded variable $3 \leq x_1 \leq 5$.
\begin{array}{l}
\text{Maximize} & Z = -15x_1 - 10x_2 - 8x_3 - 4x_4\\
\text{subject to:}& \\
&-3x_1 - 5x_2 - 3x_3 \leq -5\\
&-5x_1 - 2x_2 - 6x_4 \leq -3\\
&x_1 \geq 3\\
&x_1 \leq 5\\
&x_1, x_2, x_3, x_4 \geq 0,
\end{array}
Now, by performing the dual simplex algorithm the problem is solved in four iterations.

To try that yourself please, took a look at this link.