Answer:
DF = 4
Explanation:
You want DF when L is the midpoint, LD = x-3 and LF = 2x-8.
Congruent segments
Segments DL and LF are marked the same, so are congruent. Using the given expressions, we have ...
LF = LD
2x -8 = x -3
x = 5 . . . . . . . . add 8-x to both sides
Then the measures of the segments are ...
LF = 2(5) -8 = 2
LD = 5 -3 = 2
DF = DL +LF = 2 +2 = 4
The length of DF is 4 units.