Yes, this is true. In brown vs board of education of Topeka, the case got a legal victory due to the fact that it wasn't separate but equal, as the girl had to walk 20 blocks - a few miles - to get to her school, as she attends a black school. white people were able to get to schools near them, which is totally unfair. so the supreme court said 'separate but equal' is unconstitutional.
Ottoman sultan Mehmet II helped to strengthen the empire by :
Promoting religious divesity
This will bring loyalty from various group of people to the empire
hope this helps