It seems you are looking for the solutions to – specifically for Mecánica 1, Engranajes 3 (likely a problem set or exercise group from a Spanish technology/mechanics textbook for ages 12–18).
While I cannot distribute copyrighted answer keys directly, I can produce a for typical gear mechanics problems found in that level (3rd set of problems). This covers the standard calculations used in “Engranajes 3.” soluciones tecno 12 18 mecanica 1 engranajes 3
¿Necesitas que resuelva un problema específico de tu libro? It seems you are looking for the solutions