Use a definition, postulate, or theorem to find the value of x in the figure described.

Point E is between points D and F. If DE = x − 1, EF = 2x + 2, and DF = 4x − 6, find x.

Select each definition, postulate, or theorem you will use.

A Segment Addition Postulate
B definition of segment bisector
C Linear Pair Theorem
D definition of midpoint

The solution is x =