Dilbert invests a total of $21,500 in two accounts paying 14% and 9% annual interest, respectively. How much was invested in each account

Question

Dilbert invests a total of $21,500 in two accounts paying 14% and 9% annual interest, respectively. How much was invested in each account if, after one year, the total interest was $2,710.00.

$
was invested at 14% and
$
was invested at 9%.

Answer 1

Let x = the amount invested at 14%

Let y = the amount invested at 9%

x + y = 21,500     x = 21,500 - y

.14x + .09y = 2710    Multiply both sides of this equation by 100 to remove the decimal points.

14x + 9y = 271,000

14(21,500 - y) + 9y = 271,000

301,000 - 14y + 9y = 271,000

-5y = -30,000

y = $6000

x = 21,500 - 6000

x = $15,500