Question

You invested $17,000 in two accounts paying 6% and 7% annual interest, respectively.

If the total interest earned for the year was $1160, how much was invested at each rate?

Answer 1

Total Earnings = 18,160

1) 1.07 * principal1 * + 1.06 * principal2= 18,160

2) principal1 + principal2 = 17,000

We'll multiply equation 2) by -1.06

2) -1.06*principal1 -1.06*principal2 = -18,020 then adding equation 1)

1) 1.07 * principal1 * + 1.06 * principal2= 18,160

.01*principal1 = 140

principal 1 = 14,000

and therefore principal 2 = 3,000

Explanation: