In mathematics, reading the theory is only 20% of the work. The "Corrigés" (detailed solutions) serve several purposes: Methodology:
Many French universities openly share their first-year polycopiés de cours with corrected exercises. One excellent example is the "Polycopié de Mathématiques Générales" by various authors (e.g., Sylvain Arguillère, or the classic "Mathématiques pour économistes" by Sylvestre Kone). Mathematiques Generales Cours Et Exercices Corriges Pdf
The "General" nature of the title is accurate—it covers the core syllabus required for almost any first-year science degree with a heavy mathematical component. In mathematics, reading the theory is only 20% of the work