Calculate a 30-year loan of 520,000 yuan with an annual interest rate of 0.4%, and how much you need to pay back each month. Assume that the total loan amount is P (principal) and the monthly repayment amount is set to M.

The average capital repayment method is used to calculate the monthly repayment amount. The monthly payment formula of M is: M equals (P/n) plus P minus (I minus 1) times (P/n) times R.

R is the monthly interest rate (annual interest rate/12), n is the total number of months (years multiplied by 12), and I is the current number of months (1 for the first month, 2, ... for the second month, and n for the nth month).

According to the subject conditions, p = 520,000, the annual interest rate is 0.4% (decimal 0.004), and the loan period is 30 years, which is calculated by substituting into the formula.

So the calculation result is that 173.38+0 yuan needs to be paid every month.