They are using a of the book provided by a school library.
They are using legacy practice problems that remain relevant for general mathematical understanding. Important Note gdz po algebre spishu.ru makarychev 9 klass 2010 god
Yu. N. Makarychev’s algebra textbooks are a standard for Russian middle schools. The 9th-grade curriculum typically covers quadratic functions, equations and systems of equations, power functions, and elements of combinatorics and probability. They are using a of the book provided by a school library