Please explain without using Excel. Please explain how to get P and how to do amortization worksheet on BA2plus if possible.

Bert Nurney borrows 10000 and agrees to repay the loan over 10 years with interest at an annual effective rate of 8%. a loan payment is to be made at the end of each year for 10 years. The payments are to be level for the first 5 years then in the 6th through 10th years each payment will be twice as large as the payment amount during the first 5 years. (Thus the repayment schedule consists of 5 payments of P followed by 5 payments of 2P).

What is the outstanding balance of Bert's loan at the end of 8 years??In other words how much does Bert still owe immediately after he makes the 8th loan payment?