you plan to buy a house in december $2023.$ the sale price is $$650,000.$ you need to pay $20\%$ downpayment and borrow the additional $80\%$ from bank of america with a $30$ year $7\mathrm{.}2\%$ fixed rate mortagage loan. you need to pay an equal monthly payment starting from January $1,2024$ for a total of $30$ years.