Give the iupac name

Dear student. (iii.) In this compound The main chain is 4 carbon containing with a - COOH group at position 1 The name of the compound is thus, 2-methyl-3-bromo butanoic acid. ( iv) . In this compound there is an aldehyde group in the parent chain and a methyl group at position 3. So, the name of the compound is, 3-methylbutanal. Please post the remaining queries in separate threads. Regards