If you have access to the solutions, use them as a , not a crutch. Here is the "Active Study" method:
If your answer differs from the manual, don't just correct the number. Track back through the steps to see if the error was in the KVL loop definition or a simple sign error. If you have access to the solutions, use
The textbook "Principles and Applications of Electrical Engineering" by Giorgio Rizzoni covers a wide range of topics in electrical engineering, including: use them as a