SOLUTION: 2. A business invests $10,000 in a savings account for two years. At the beginning of the second year, an additional $3500 is invested. At the end of the second year, the account

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: 2. A business invests $10,000 in a savings account for two years. At the beginning of the second year, an additional $3500 is invested. At the end of the second year, the account      Log On


   

Question 165264: 2. A business invests $10,000 in a savings account for two years. At the beginning of the second year, an additional $3500 is invested. At the end of the second year, the account balance is $15,569.75. What was the annual interest rate?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let r= annual interest rate
At the end of the first year, there is 10000%2A%281+%2B+r%29
in the account
At the beginning of the 2nd year, 10000%2A%281+%2B+r%29+%2B+3500
is in the account
At the end of the 2nd year, there is 13500%2A%281+%2B+r%29%2A%281+%2B+r%29
in the account
13500%2A%281%2Br%29%5E2+=+15569.75
%281+%2B+r%29%5E2+=+1.1533
1+%2B+r+=+1.0739
r+=+.0739
The annual interest rate is 7.4 %