Sorry, I'm new to this forum and didn't know about this rule.
For the first item (b), I thought about first reacting with a strong base (:X), resulting in a negative charge, wich would make the double bond, after Br- leaving the molecule (E2 mechanism, I think?). But then, I don't know how to proceed to form the second double bond, on the cycle.
For the second item (c), I thought about doing an oxidation with KMNO4 and heat, but I saw a similar reaction and apparently whens this compound reacts with a double bond, it breaks it in two, generating the carboxilic acid and CO2? Does that make sense?
Thanks for the *delete me*