What physical feature separated cultural groups from each other in the balkans?

Mountains.  

Explanation:

Balkanization refers to the fragmentation of ethnic societies caused partly by the compartmentalization created by the mountainous geography.

That´s why ethnic diversity is the main social and political characteristic in this area. The Balkan nations emerged from many diverse ethnic roots from previous indigenous civilizations.

f(-4) = -1

f(-1) = -4

f(1) = 4

Step-by-step explanation:

We need to find the y value for the x values

f(-4) means find the y value for x= -4

f(-4) = -1

f(-1) = -4

f(1) = 4