Question

Alice invests $8000  in two certificates of deposit; the interest on the first certificate is 

2% , and the interest on the second is  3% . Let's denote the amount she invests in the first certificate by  x . Then the amount she invests in the second certificate is _________   .  The interest she receives on the first certificate is __________  ,  and the interest she receives on the second certificate is ______________  .  So a function that models the total interest she receives from both certificates is  y =___________   .

Answer 1

1. 8000-x (You invest x in the first, then you have 8000-x more to make up for)
2. 0.02x (Interest * how much you invested)
3. 0.03(8000-x) (Interest * how much you invested)
4. 0.02x+240-0.03x
=240-0.01x