Question

Suppose you invest money in two accounts. One of the accounts pay 8% annual interest, whereas the other pays 10% annual interest. If you have $7,000 more invested at 10% than you invested at 8%, how much do you have invested in each account if the total amount of interest you earn in a year is $1,240?

Answer 1

Call x the money you invest in the 8% account, then x+7000 is the money you invest in the 10% account.
.1(x+7000) + .08x = 1240
.1x + 700 + .08x = 1240
.18x = 540
x = 3000
$3000 in 8% account and $10000 in 10% account.

Answer 2

ok thanks