harleyload wrote:A man invests $22,000 into two accounts. One account pays 6% simple interest and the other pays 7% simple interest. The annual interest earned is $1,420. How much is invested in each account?
To learn how to set this up and solve it, try
this lesson on "investment" word problems.
Once you've learned the basic terms and techniques, you'll see how to set up the grid:
+----------+-----------+------+---+-----------------+
|##########| P * r * t = I |
+----------+-----------+------+---+-----------------+
| 6% acct. | x | 0.06 | 1 | 0.06x |
+----------+-----------+------+---+-----------------+
| 7% acct. | 22000 - x | 0.07 | 1 | 0.07(22000 - x) |
+----------+-----------+------+---+-----------------+
| total | 22000 |######| 1 | 1420 |
+----------+-----------+------+---+-----------------+
Note that the expression for the amount of the principal P invested in the 7% account comes from
translating the fact that, after "x" of the total was put into the other account, only (total) - x remained for the 7% account.

Since the total interest earned was the sum of the interest on each of the two investments, add the two "interest" expressions, and set equal to the given total. Then
solve the resulting linear equation for the value of "x". Back-solve for the other investment amount.
If you get stuck, please reply showing how far you have gotten. Thank you!
