please explain how this is done;here is the answer

2017

Dec. 31	Services Revenue	404	44,000
	Income Summary	901		44,000
	Close the revenue account
31	Income Summary	901	33,100
	Depreciation ExpenseEquipment	612		3,000
	Salaries Expense	622		22,000
	Insurance Expense	637		2,500
	Rent Expense	640		3,400
	Supplies Expense	653		2,200
	Close the expense accounts
31	Income Summary	901	10,900
	T. Cruz, Capital	301		10,900
	Close income summary
31	T. Cruz, Capital	301	7,000
	T. Cruz, Withdrawals	302		7,000
	Close the withdrawals account

Exercise 4-9 Preparing closing entries and a post-closing trial balance P2 P3 Page 176 The following adjusted trial balance contains the accounts and balances of Cruz Company as of December 31, 2017, the end of its fiscal year. (1) Prepare the December 31, 2017, closing entries for Cruz Company. Assume the account number for Income Summary is 901. (2) Prepare the December 31, 2017, post-closing trial balance for Cruz Company No. Account Title Debit Credit 10 Cash 126 128 Prepaid insurance 167 Equipment 168 Accumulated depreciation-Equipment 301 302 T. Cruz, Withdrawals 404 Services revenue 612D 622 Salaries expense 637 Insurance expense 640 Rent expense 652 Supplies expense $19,000 13,000 3,000 24.000 Supplies S 7,500 47.600 T. Cruz, Capital 7,000 44,000 Depreciation expense-Equipment 3.000 22,000 2,500 3.400 2.200 Totals 99.100 $99,100 Check (2) T. Cruz, Capital (ending), $51,500; Total debits, $59,000