Answer:
$7,000 is invested at 5% interest
$14,000 is invested at 9% interest
Explanation:
Let A represent the amount of interest that was invested at 5%
= 5/100
= 0.05
Then 21,000-A will represent the amount that was invested at 9%
= 9/100
= 0.09
The amount invested at 5% can be calculated as follows
0.05A + 0.09(21,000-A)= 1,610
0.05A + 1,890 -0.09A= 1,610
Collect the like terms
0.05A - 0.09A = 1,610-1,890
-0.04A= -280
Divide both sides by the coefficient of A which is -0.04
-0.04A/-0.04= -280/-0.04
A= $7,000
Recall that 21,000-A represents the amount invested at 9%, since we have gotten the value of A then, It can be inputed into the expression
= $21,000-$7,000
= $14,000
Hence $7,000 was invested at 5% interest and $14,000 was invested at 9% interest.
