Please explain the reasoning!

Milan Crone opened a public relations firm called Tuney Town on August 1, 2016. The following amounts summarize her business on August 31, 2016: During September 2016, the business completed the following transactions: Analyze the effects of the transactions on the accounting equation of Tuney Town. Analyze the events chronologically, one transaction at a time. Beginning with transaction a., calculate the balance in each account after analyzing the effect of the transaction on the accounting equation. (Complete only the necessary answer boxes for your transaction lines. [Do not enter any zeros for your transaction lines] Carry down all balances to the "Bal." line, including zero balance accounts, entering a "0" for any zero balances. Enter a decrease in an account with a minus sign or parentheses. Abbreviations used: A/P = Accounts Payable; A/R = Accounts Receivable; Adv. = Advertising; Cap. = Crone, Capital; Exp. = Expense; Liab = Liabilities; Rev. = Revenue; Sup. = Supplies; Withdr. = Crone, Withdrawals.) Milan Crone contributed $9,000 cash in exchange for capital. Performed service for a client and received cash of $900. Paid off the beginning balance of accounts payable. Purchased office supplies from OfficeMax on account, $200. Collected cash from a customer on account, $1,500. Milan withdrew $1, 200. Consulted for a new band and billed the client for services rendered, $4,500. Recorded the following business expenses for the month: Paid office rent: $600. Paid advertising: $400