Answer:
Wow - you are asking a LOT of questions. The Monthly Payment Formula is really tricky so I'll solve that for you.
The time of the loan = 20 years * 12 = 240 months
We have to convert the annual rate to a monthly rate and that is done by:
monthly rate = 5.125 / 1,200 = 0.00427083333333333
Monthly pmt = 0.00427083333333333 + [0.00427083333333333 / (1.00427083333333333^240) -1 ] * 420,000
Monthly pmt = 0.00427083333333333 + [0.00427083333333333 / 2.7810190076 -1] * 420,000
Monthly pmt = (0.00427083333333333 +0.0023979718) * 420,000
Monthly pmt = 2,800.90
A calculator to double check is here: https://www.1728.org/calcloan.htm
Step-by-step explanation: