This is the 10146th most frequent Turkish word.
başkanlarıyla
"With their presidents/chairpersons."
In this sentence, 'başkanlarıyla' combines 'başkanları' (their president) and 'ile' (with), showing possession and association.
Öğrenciler, okul başkanlarıyla toplantıya katıldılar.
The students attended the meeting with their school president.
Here, 'başkanlarıyla' indicates that the firms acted in coordination with the presidents of the associations.
Firmalar, dernek başkanlarıyla anlaşma imzaladı.
The companies signed an agreement with the association presidents.
In this example, 'başkanlarıyla' implies collaborative action between the people and their neighborhood leaders.