Answer:
33
Step-by-step explanation:
Along the left side we have that the 2 segments split by the segment x are congruent to one another. Same with the segments split on the right. That means, logically, that the segment x is exactly halfway between the 2 lines with lengths of 18 and 48. Half way between 18 and 48 is the average of those 2 numbers, which is 33.
