You can download the official audio tracks for the 5-7 grade UMK via Rosuchebnik .

For reviewing the actual textbook content or finding supplementary materials:

features video explanations for homework assignments in both the 5th and 6th grade curricula. Digital Textbook & Materials

provides a comprehensive collection of answers for the 5th grade and 6th grade textbooks, as well as the accompanying workbooks .

Online resources for by M.Z. Biboletova include digital textbooks, workbooks, and ready-made homework solutions (GDZ). Ready-Made Homework Solutions (GDZ)