Answer:
10
Step-by-step explanation:
In triangle ACE, B and F are mid points of sides CA and CE respectively.
Therefore, BF is the mid segment of triangle ACE.
By Mid-segment formula:
AE =2BF
5x - 4 =2*23
5x - 4 = 46
5x = 46+4
5x = 50
x = 50/5
x = 10