These are the most popular "classic" sites. They usually provide photos of handwritten solutions so you can see the process, not just the answer.
Whether you are in 5th grade or 11th, the "Prosveshchenie" (Просвещение) textbooks—often edited by authors like —are the gold standard in schools. 🔍 Where to find the best solutions: gdz po russkomu iazyku klass prosveshchenie
Ladyzhenskaya (Ладыженская), Trostentsova (Тростенцова). These are the most popular "classic" sites