SOLUTION: You invested ​$29,000 in two accounts paying 6% and 9% annual​ interest, respectively. If the total interest earned for the year was $1980, how much was invested at ea

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: You invested ​$29,000 in two accounts paying 6% and 9% annual​ interest, respectively. If the total interest earned for the year was $1980, how much was invested at ea      Log On


   



Question 1044420: You invested ​$29,000 in two accounts paying 6% and 9% annual​ interest, respectively.
If the total interest earned for the year was $1980, how much was invested at each​ rate?

Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
You invested ​$p in two accounts paying x% and y% annual​ interest, respectively.
If the total interest earned for the year was $z, how much was invested at each​ rate?

s and t, the two quantities invested
s%2Bt=p

Account for the amount of interest earned:
%28xs%2Byt%29%2F100=p
xs%2Byt=100p

Solve this system for s and t:
system%28s%2Bt=p%2Cxs%2Byt=100p%29

Answer by MathTherapy(10555) About Me  (Show Source):
You can put this solution on YOUR website!

You invested ​$29,000 in two accounts paying 6% and 9% annual​ interest, respectively.
If the total interest earned for the year was $1980, how much was invested at each​ rate?
Let amount invested at 6% be S
Then amount invested at 9% = $29,000 - S
The following INTEREST equation is then formed: .06S + .09(29,000 - S) = 1,980
.06S + 2,610 - .09S = 1,980
.06S - .09S = 1,980 - 2,610
- .03S = - 630
S, or amount invested at 6% = %28-+630%29%2F%28-+.03%29, or highlight_green%28%22%2421%2C000%22%29
Amount invested at 9%: $29,000 - $21,000, or highlight_green%28%228%2C000%22%29
It is that simple!