We know that
E is midpoint of DF, that means DE is equal to EF, so we can form the following equation
![DE=EF](https://img.qammunity.org/2023/formulas/mathematics/college/d03c9oa09e9ww5zggfzcskcjy3lo9whlc6.png)
Replacing the given equations, we have
![\begin{gathered} 2x+4=3x-1 \\ 4+1=3x-2x \\ x=5 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/hxywb3tts5f0z7mwh2f28fuozjf6spbvk5.png)
Now, we replace this value in each equation to find each part of the segment.
![\begin{gathered} DE=2x+4=2(5)+4=10+4=14 \\ EF=3x-1=3(5)-1=15-1=14 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/af77f66uyw272ojdz01tj5nolyaat2pp96.png)
Therefore, each part of the segment is 14 units, and DF is 28.