Solving a formula for a specific variable

Question

Nadia makes two separate investments, one paying 4 percent and the other paying 12 percent simple interest per year. She invests a total of $8300, and her annual interest earnings are $684. How much did she invest at each rate?

Answer 1

I provided a solution to a similar problem you posted (10% and 33%).

Use that as a model and solve this one.

If you have a specific question, ask.