Quick Math Question - Principal Paydown & Appreciation

[Stephen Brown]

I'm reading The Millionaire Real Estate Investor by Gary Keller and I'd like to know if someone could help me out by providing the formulas that he used to calculate his answers.

($100,000 price, 20% discount on purchase price, 20% down payment, 5% annual appreciation of value and rent, initial rent at
0.8% of value, expenses/vacancy at 40% of rental income, 30 year loan with interest rate of 7.43%)

Annual appreciation of property is $7,759

Annual Principal paydown is $1,165

For principal paydown, I'm getting 577.92 (I'm doing a loan payment for 30 years @ 7.43% minus 64k * .0743/12 for interest = 48.16 payment per month * 12 months = 577.92)

Thanks for answering my newbie question!