Question 1192911
i believe i was able to solve this using excel.
below are displays of excerpts from that excel analysis.


<img src = "http://theo.x10hosting.com/2022/040411.jpg" >


<img src = "http://theo.x10hosting.com/2022/040412.jpg" >


<img src = "http://theo.x10hosting.com/2022/040413.jpg" >


<img src = "http://theo.x10hosting.com/2022/040415.jpg" >


the display shows that the payments are 1400 dollars a month starting at end of month 1.
it shows that the interest part of the payment is 666.76 and the principal part of the payment is 1033.24 at end of month 25.
it shows that the payment becomes 1700 starting at the end of month 61.
it shows that the remaining balance is equal to 0 at the end of month 120.


let me know if you have any questions.
theo