Final answer:
Shoji invested $4000 at 9% interest and $3000 at 6% interest.
Step-by-step explanation:
Let's assume that Shoji invested x dollars at 9% interest and (7000 - x) dollars at 6% interest
The interest obtained from the 9% investment is 0.09x dollars.
The interest obtained from the 6% investment is 0.06(7000 - x) dollars.
According to the problem, the interest obtained from the 6% investment is half of the interest obtained from the 9% investment. So, we can write the equation:
- 0.06(7000 - x) = (1/2) * 0.09x
Solving the equation, we get x = 4000.
Therefore, $4000 was invested at 9% interest and $3000 was invested at 6% interest.