Step-by-step explanation:
In the sentence, Julio is telling somebody that they'll be sitting next to each other, because the person has the seat number 26B.
In Spanish, you also "have a seat" - tener un asiento.
Answer:
Now, what we need to do is to conjugate te ver "tener" correctly so that it fits correctly:
Julio: Estás al lado de mí. Tienes el asiento 26 B. --> Since Julio is talking to somebody else, in second person (estás - you are), the verb should be conjugated accordingly.
Hope it helped,
BioTeacher101