I want full-deep-efficient explanation of each step

i.e. why Interest expense is 200? I know we get it from 700-500=200 but why?

also why interest payable is 500?

I need a step by step to guide me how can I deal with this kind of questions

g. Lorring has incurred $500 of interest expense on a $700 interest payment due on January 15. Journalize the subsequent journal entry that Lorring will record on January 15. Date Accounts and Explanation Debit Credit Jan. 15 Interest Expense 200 Interest Payable 500 Cash 700