Can you explain and show the calculation process about how to get the Retained Earning $144,510?

Depreciation Expense 8,000 Accumulated Depreciation 18,100 Salaries Payable 25,650 Cash Supplies Supplies Expenses 21,050 153,000 12,200 Salaries Expense 1,610,000 Prepaid Expenses 10,200 Interest Expense 17,200 Retained Earnings Accounts Receivable 225,400 Consulting Fees Revenue 2,564,200 ? Income Taxes Payable 3,030 Travel Expense 23,990 Buildings and Equipment 623,040 Utilities Expense 25,230 Gain on Sale of Land 6,000 Unearned Consulting Fees 32,500 Land Investment Income 10,800 Accounts Payable 96,830 60,000 Common Stock Additional Paid-in Capital 220,000 Professional Development Expense 18,600 3,370 Rent Expense (on leased computers) 152,080 Notes Payable 160,000 Investments 325,000