Hmm... suspicious that no one has posted help request on page 56. I am lost.
Do i see it right, that the solution to this page is needed nowhere else?
Yes, but not completing it does mean not completing the book.
IMO the demanded answer is not scientificaly correct.
Probably is like erase a word from paper not the actual chemical reaction
What's that? RIddles are more wordplay than accurate scientific equations? Never...