I don't understand how to solve this question can you help mealso with journal entry 12-15?

Required information [The following information applies to the questions displayed belo W.] The following transactions pertain to Smith Training Company for Year 1: Jan. 30 Established the business when it acquired $54,000 cash from the issue of common stock. Feb. 1 Paid rent for office space for two years, $16,400 cash. Apr. 10 Purchased $800 of supplies on account. July 1 Received $22,500 cash in advance for services to be provided over the next year. 20 Paid $600 of the accounts payable from April 10. Aug. 15 Billed a customer $10,000 for services provided during August. Sept.15 Completed a job and received $3,100 cash for services rendered. Oct. 1 Paid employee salaries of $33,500 cash. 15 Received $7,600 cash from accounts receivable. Nov. 16 Billed customers $30,500 for services rendered on account. Dec. 1 Paid a dividend of $800 cash to the stockholders. 31 Adjusted records to recognize the services provided on the contract of July 1. 31 Recorded $2,050 of accrued salaries as of December 31. 31 Recorded the rent expense for the year. (See February 1.) 31 Physically counted supplies; $120 was on hand at the end of the period.