Answer: 9v+45
Step-by-step explanation:
Distribute
9(v+5) = 9v+45
Collin invested $5529 in the account paying 2% and $2171 in the account paying 9% interest.
<u>Explanation:</u>
Let x be amount invested at 2%
So, 7700 - x will be the amount invested at 9%
0.02(x) + 0.09(7800 - x) = 315
0.02x + 702 - 0.09x = 315
-0.07x = -387
x = $5529
7700 - x = 7700 - 5529
= $2171
Collin invested $5529 in the account paying 2% and $2171 in the account paying 9% interest.