I have worked it out via a commercial mathematics formula but maybe you have to do it using GP formula.
If you want me to work it out a different way let me know.
(Also, i often make careless mistakes so if you think that i am wrong you might be right. )
A=100000
i=10.5% = 0.105
n=25
R=yearly repayment
A = R * (a angle n at i)
(a angle n at i) = [1-(1+i)^(-n)] / i
=[1-1.105^(-25)] / 0.105
=8.739019 (4 dec places)
so
100000 = R * 8.739019
R = 100000 / 8.739019
= $11,442.93
+118724 
