SOLUTION: I'ts been a while since I've solved these kinds of questions (ok 20+ years!) so I need a refresher. I looked a similar problems on-line, but am struggling with how to set it up.

Algebra.Com
Question 213021: I'ts been a while since I've solved these kinds of questions (ok 20+ years!) so I need a refresher. I looked a similar problems on-line, but am struggling with how to set it up. Here's the problem:
Sam invested $5000 for one year, part at 9% annual interest and the rest at 12% annual interest. The interest from the investment at 9% was $198 more than the interest from the investment at 12%. How much money did she invest at 9%?

Found 2 solutions by ankor@dixie-net.com, MathTherapy:
Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
Sam invested $5000 for one year, part at 9% annual interest and the rest at 12% annual interest.
The interest from the investment at 9% was $198 more than the interest from the investment at 12%.
How much money did she invest at 9%?
:
Let x = amt invested at %9
Total invested given as 5000, therefore
(5000-x) = amt invested at 12%
:
.09x - 298 = .12(5000-x)
.09x - 298 = 600 - .12x
.09x + .12x = 600 + 298
.21x = 898
x =
x = $4,276.19 invested at 9%
then
5000 - 4276.19 = $723.08 invested at %12
:
:
Is this true? find the interest of each
.09*4276.19 = 384.86
.12 * 723.08 = 86.86
-------------------
difference = 298; confirms these solutions

Answer by MathTherapy(10556)   (Show Source): You can put this solution on YOUR website!

Let the amount invested at 9% be N
Then the amount invested at 12% is 5,000 - N

Now, the interest earned at 9%, less $198 equals the einterest earned at 12%

Therefore, we'll have: .09N - 198 = .12(5,000 - N)

.09N - 198 = 600 - .12N

.09N + .12N = 600 + 198

.21N = 798

= $3,800

We can conclude that N, or the amount invested at 9% is: $
--------
Check
--------
Amount invested at 9% = $3,800, and interest earned at 9% = (.09 * 3,800) = $342

Amount invested at 12% = $1,200 (5,000 - 3,800), and interest earned at 12% = (.12 * 1,200) = $144

Difference: $198 ($342 - $144), with 9% interest earned ($342) being $198 more than 12% interest earned ($144).

RELATED QUESTIONS

Use slopes to show that the square with virtices at (-2,5), (4, 5), (4, -1), and (-2, -1) (answered by stanbon)
i am not sure if this is the right category but here it goes. I am in grade 9 math and i (answered by ankor@dixie-net.com)
The fill weight of a certain brand of adult cereal is normally distributed with a mean of (answered by Boreal)
OK if someone can help me please understand how to do these I have a lot of problems... (answered by josgarithmetic)
The minute hand of a clock is 7 inches long. How far does the tip move in 20 minutes? In... (answered by lwsshak3)
solving one step equations. I need a refresher to help my daughter with homework!! It's... (answered by Boreal,math_helper)
This is my first time submitting anything, so bare with me and let me no if I am doing... (answered by jim_thompson5910)
Hello, I have been working on a more complex equation and have worked it down to the... (answered by Alan3354)
Y Intercept: 6x^2+12x+6 It's been a while since i've done this and i need some... (answered by Alan3354)