To solve this problem, we need to determine the length of the line segment represented by the unknown variable x.
Given that the length of the line segment is 9mm, we can set up the equation as follows:
2x + 5 = 9
Let's solve for x:
2x = 9 - 5
2x = 4
To isolate x, we divide both sides of the equation by 2:
x = 4 / 2
x = 2
The value of x is 2.
The answer is: 2
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
What is the positive difference between the median and the mode of the data given in the stem and leaf plot below? In this plot $5|8$ represents $58.$

\begin{tabular}{|c|c|}\hline
\textbf{Tens} & \textbf{Units} \\ \hline
1 & $2 \hspace{2mm} 3 \hspace{2mm} 4 \hspace{2mm} 5 \hspace{2mm} 5$ \\ \hline
2 & $2 \hspace{2mm} 2 \hspace{2mm} X \hspace{2mm} \hspace{2mm} \hspace{2mm} \hspace{1.5mm}$ \\ \hline
3 & $1 \hspace{2mm} 1 \hspace{2mm} 8 \hspace{2mm} 9 \hspace{2mm} \hspace{1.9mm}$ \\ \hline
4 & $ 0 \hspace{2mm} 1 \hspace{2mm} 2 \hspace{2mm} 3 \hspace{2mm} \hspace{1.9mm}$ \\ \hline
5 & $ 2 \hspace{2mm} 8 \hspace{2mm} 9 \hspace{2mm} \hspace{2mm} \hspace{2mm} \hspace{1. The length of the line segment is 9mm. What is the value of unknown variable X?

### Answer:
