9514 1404 393
Answer:
EF = 58
Step-by-step explanation:
We assume point E lies on line segment DF, so that ...
DF = DE +EF
9x -39 = 47 +(3x +10)
6x = 96 . . . . . . . . . . . . . . . subtract (3x-39)
x = 16 . . . . . . . . . . . divide by 6
EF = 3×16 +10 = 58
