You can find current editions at OZON or Wildberries .
The core 11th-grade book contains 18 independent and 4 control works, each typically featuring four variants. l.a. kirik. reshenie za 11 klass. gotovye domashnie zadaniia
Full step-by-step solutions are less common in the primary textbook but are sometimes found in "Problems with Examples of Solutions" (Задачи с примерами решений) for 10-11th grades. You can find current editions at OZON or Wildberries