Answer:
The payments will be for  8,536.485 to achieve an 8% return on the investment.
Explanation:
we will calcualte the value of the loan at the beginning of year 4:
carrying value x (1+rate) - payment = year-end carrying value
((35,000 x 1.08 - 2,500) x 1.08-5,000) x1.08-7,500 =
(35300 carrying value at 1st year-end x 1.08-5,000) x1.08-7,500 =
33124 carrying value at 2nd year-end x 1.08-7,500 = 28273.92
Now, this will be paid with a 4 years annuity of equal payment at 8% discount rate
[tex]PV \div \frac{1-(1+r)^{-time} }{rate} = C\\[/tex]
PV Â $28,273.92
time 4 years
rate     0.08
[tex]28273.92 \div \frac{1-(1+0.08)^{-4} }{0.08} = C\\[/tex]
C Â $ 8,536.485