Answer:
$8,400
Step-by-step explanation:
The interest can be calculated using the following equation:
![I=\text{P}\cdot r\cdot t](https://img.qammunity.org/2023/formulas/mathematics/college/j7sumi74br5ed3f7jjaom6gb1fpo2e8jhg.png)
Where P is the original amount of the loan, r is the interest rate, and t is the time that the person tool to pay it back.
So, we can replace I by $1,050, r by 2.5% or 0.025, and t by 5 years. Then:
![1050=P\cdot0.025\cdot5^{}](https://img.qammunity.org/2023/formulas/mathematics/college/nxegf0vqrsb5v0r5rgyvol0dhck88n6vid.png)
Finally, we can solve for P as:
![\begin{gathered} 1050=P\cdot0.125 \\ (1050)/(0.125)=(P\cdot0.125)/(0.125) \\ 8400=P \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/paz7azlahbbjjq34bgmwliqnr8tgot268h.png)
Therefore, the original amount of the loan was $8,400