If I borrow $26,400 @ 7% interest and make payments of $300 how much will I have left owing after 19 months.

1 answer

Poor wording
Is the payment made monthly?
Was the first payment made one month after the loan was taken out?
Is the interest compounded monthly?

I will assume those three important facts

i = .07/12 = .00583333...

amount owing after 19 months
= 26400(1.0058333)^19 - 300( 1.00583333..^19 - 1)/.0058333.
= $ 23,475.44

The main reason that your balance is still so high is that the payment of $300 at the beginning is made of over $150 in interest you have to pay each month.
e.g. for the first month the interest would be $154