Looks good to me
1. In the original equation the argument of the first log-term is missing. According to your calculations it seems to be 1.
2. All calculations are correct - but
3. You can control your work yourself by plugging in your solution into the original equation. If you get a true statement then your work is correct.
....
121b) May I ask you a favour? Sometimes it is very difficult for me to read your questions. Why don't you use simply black colour for writing?