Answer: The monthly payment is $859.52
(A) The unpaid balance after 10 years is $109,166.29
(B) The unpaid balance after 20 years is $73,374.27
Explanation:
The answer provided below has been developed in a clear step by step manner.Step: 1
PV = Mortgage balance = $126,626
n = 30*12 = 360 months
r = Monthly interest rate = 7.2%/12 = 0.6%
Monthly payment = [r*PV] / [1 - (1+r)^-n]


P = Monthly payment = $859.52
n = 30*12 = 360 months
r = Monthly interest rate = 7.2%/12 = 0.6%
x1 = Payments made = 10*12 = 120 months
x2 = Payments made = 20*12 = 240 months
x3 = Payments made = 25*12 = 300 months
Unpaid Balance after 10 years = P * [1 - (1+r)^-(n-x1)] / r


Unpaid Balance after 20 years = P * [1 - (1+r)^-(n-x2)] / r


Unpaid Balance is the present value of the remaining payments