GP要怎样算房贷啊？

plouffle0789

借50，000
还15年
利息9巴仙

the rate of interest is calculated based on the amount outstanding at the beginning  of each year.
ASSUMING THAT THE RATE OF THE INTEREST IS FIXED FOR THE ENTIRE DURATION OF THE LOAN.FIND THE AMOUNT HE HAS TO REPAY TO THE BANK.

sunsilk_cv

借50，000
还15年
利息9巴仙

the rate of interest is calculated based on the amount outstanding a ...
plouffle0789 发表于 23-10-2011 03:01 PM

T1(第一年) = 50000+50000(0.09) - x (要还的钱)
                   = 50000(1.09) - x

T2 = T1+T1(0.09) - x
     = T1(1.09) - x
     = [50000(1.09) - x](1.09) - x
     = 50000(1.09)^2 - x(1.09) - x

T3 = T2 + T2(0.09) - x
     =T2(1.09) - x
     = [50000(1.09)^2-x(1.09)-x](1.09) - x
    = 50000(1.09)^3 - x(1.09)^2 - x(1.09) - x

T15 = 50000(1.09)^15 - x(1.09)^14 - x(1.09)^13 - ....... - x(1.09) - x
x + x(1.09) +.......+ x(1.09)^13 + x(1.09)^14 = 50000(1.09)^15

       x [1.09^15-1 / 1.09 - 1] = 50000(1.09)^15

过后找x 的value就是一年要换的是多少钱了。