Answer:
26
Step-by-step explanation:
If you take away numbers from each side you get to the answer
ex:
21 and 38 then 23 and 29, then 23 and 28, etc, until you're left with one number in the "Middle". With this question there was two numbers left, but they were both 26, so it ends up being 26, but if they were different you would add the two numbers together and divide by two.
