Answer:
(b) EF = 5
Explanation:
Given point F lies on segment EG, you want to find EF when FG = 12 and EG = 17.
Segment addition
The segment addition postulate tells you the whole is the sum of the parts. That is ...
EF +FG = EG
EF +12 = 17 . . . . . substitute given lengths
Subtracting 12 from both sides of the equation, we have ...
EF = 5