Answer:
The person has to invest $5000 at 9% and $7000 at 10%.
Explanation:
As stated in the problem, we have an ammount C that the person invest at 9% and an ammount (C+2000) that it is invested at 10%.
To gain $1150 a year, the ammount C needs to satisfy this equation:

Applying distributive property,


So the person has to invest C=$5000 at 9% and (C+2000)=$7000 at 10% to gain $1150 of interest yearly.