The minimum yearly repayment (MYR) for the first year is calculated as follows using the given formula:

MYR = P * r / (1 - (1 + r)^-n)

P = 50000  
r = 0.0877  
n = 7  

(1 + r)^7 = 1.0877^7 ≈ 1.80120813 (computed via successive multiplication: 1.0877^2 = 1.18309129, ^3 ≈ 1.28684840, ^4 ≈ 1.39970500, ^5 ≈ 1.52245913, ^6 ≈ 1.65597879, ^7 ≈ 1.80120813).  

(1 + r)^-7 ≈ 1 / 1.80120813 ≈ 0.55518292.  

1 - 0.55518292 = 0.44481708.  

r / (1 - (1 + r)^-n) ≈ 0.0877 / 0.44481708 ≈ 0.19715970.  

MYR = 50000 * 0.19715970 = 9857.985, which rounds to 9857.98.  

The controlling authority for the Division 7A minimum yearly repayment rule is the Commissioner of Taxation.