Emilce has invested a total of $12,000 in two savings accounts that pay 5% and 8% annual simple interest. Find the amount invested in each account knowing that a total of $840 in interest is received after one year.

Let's denote the amount invested in the 5% account as x and the amount invested in the 8% account as 12000 - x.

The interest earned from the 5% account is given by 0.05x and the interest earned from the 8% account is given by 0.08(12000 - x).

We are given that the total interest earned is $840, so we can set up the equation:

0.05x + 0.08(12000 - x) = 840

Solving the equation gives:

0.05x + 960 - 0.08x = 840

-0.03x + 960 = 840

-0.03x = -120

x = 4000

So, Emilce invested $4000 in the 5% account and $8000 in the 8% account.

\textbf{Answer:} Emilce invested $4000 in the 5% account and $8000 in the 8% account.