основные

основные

Main; basic; fundamental.

The word 'основные' here is used as an adjective modifying 'принципы' (principles), meaning 'basic, fundamental' in the context of describing primary concepts.

Основные принципы работы этой системы описаны в документе.

The basic principles of this system's operation are described in the document.

In this sentence, 'основные' is used to describe 'проблемы' (issues), implying the most important or primary concerns being addressed.

Основные проблемы были решены на встрече.

The main issues were resolved at the meeting.

Here, 'основные' acts as an adjective for 'цели' (goals), indicating primary or key targets that were the focus of the discussion.

Мы обсудили основные цели проекта во время совещания.

We discussed the main goals of the project during the meeting.