(government property disallowed business deductions for vehicle, travel, entertainment and janitorial expenses, properly disallowed deduction from rental income of passive losses from dental equipment leasing business and that marketing operation not engaged in for profit; no allocation between business and personal use of vehicles, did not establish year placed in service, failed to show travel and entertainment expenses related to dental convention, failed to substantiate other expenses; farming operation engaged in for profit and loan repayment from son should be excluded from income).