please explain where the numbers came from and the caclulations

21. Marble Co. has a total monthly gross pay of $175,000. The company withholds federal income tax at 20% for all employees. In addition, the following tax rates apply: FICA tax is 7.65% on income up to $ 128,400 and 1.45 % on income in excess of that amount. Federal unemployment tax, 0.8%; state unemployment tax, 2.7% on the first $ 7,000. Of the $175,000, $40,000 is in excess of $128,400, and $ 155,000 is in excess of the $7,000 for both unemployment taxes. Required: a. Prepare the journal entry to record salaries and employee withholding items for the month of January. b. Prepare the journal entry to record employer payroll taxes for the month of January