This is the 833rd most frequent Russian word.
связанных
"Related" or "connected."
'Связанных' describes the matters ('вопросы') that pertain to or are connected with the educational system.
Мы обсуждали вопросы, связанных с образовательной системой.
We discussed matters related to the educational system.
In this sentence, 'связанных' describes projects that have a connection to ecology.
Проекты, связанных с экологией, особенно важны.
Projects related to ecology are especially important.
The word 'связанных' here functions as a past passive participle, describing problems that are 'related' (connected) to his work.