Hello, noreen_cruz!

I have issues with this problem.

[1] You have been given the Amortization Formula?

. . .And you're expected to manipulate it algebraically? . . . in Grade 9 ?

[2] I don't agree with their numbers.

$10,000 loan to be paid over 4 years.

Monthly Payments is: .

(a) Find the monthly payment when interest rate is 8.25%

(b) What interest rate would require a monthly payment of $255?

Amortization Formula: .

. . where: .

For the 8% loan, we have: .

Then: .

So I don't trust the author(s) of this problem . . .