O---------A----------------------------------------------------------------B
<-------------------------- 44 ------------------------------->
For a scale factor of 7, we have OB = 7·OA; that is, OB is 7 times longer than OA.. The Segment Addition Postulate tells us that OB = OA + AB, so:
OB = 7·OA
OA + AB = 7·OA
Since AB = 44:
OA + 44 = 7·OA
Solve for OA. The answer is a mixed number.