Do not open the solucionario until you have spent at least 15 minutes on a problem. Struggle is necessary for learning.
The inclusion of the word is the most telling component of the query. It implies a crisis of trust. Students are aware that the internet is flooded with crowdsourced or scanned solucionarios that may have been corrupted by poor OCR (optical character recognition), omitted steps, or deliberate errors introduced to circumvent copyright detection.
Platforms like , Physics Forums , or Matemáticas y Estadística en Español often have threads where users rate different solucionarios. Look for comments like: "Este solucionario sí está bien verificado, el de la otra página tenía errores en el capítulo 7."