Question 17643: If possible, I would love some help with this problem. I need to be able to solve it with substitution. I am able to do substitution but the only problem I have is finding the equations within the problem. Thanks so much in advance! Here is the question:
Kelly invested her savings of $4800. She invested part in mutal funds, at 9% per year an the rest in GIC's, at 10% per year. At the end of the yera ,the interest from the mutual funds investment was $43 less than the interest from the GIC investment. How much was invested in each type of investment?
Found 2 solutions by IA, MathTherapy:
Answer by IA(6)   (Show Source):
You can put this solution on YOUR website! If possible, I would love some help with this problem. I need to be able to solve it with substitution. I am able to do substitution but the only problem I have is finding the equations within the problem. Thanks so much in advance! Here is the question:
Kelly invested her savings of $4800. She invested part in mutal funds, at 9% per year an the rest in GIC's, at 10% per year. At the end of the yera ,the interest from the mutual funds investment was $43 less than the interest from the GIC investment. How much was invested in each type of investment
equation:
1.09y - part of the money invested at 9% per year
1.1x - part of money invested at 10% per year
1.09y-1.1x=$43 - the difference is $43
Answer by MathTherapy(10806)  (Show Source):
You can put this solution on YOUR website!
If possible, I would love some help with this problem. I need to be able to solve it with substitution. I am able to do
substitution but the only problem I have is finding the equations within the problem. Thanks so much in advance! Here is the question:
Kelly invested her savings of $4800. She invested part in mutal funds, at 9% per year an the rest in GIC's, at 10% per year. At the end of the yera ,the interest from the mutual funds investment was $43 less than the interest from the GIC investment. How much was invested in each type of investment?
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Post from the other person:
1.09y - part of the money invested at 9% per year
1.1x - part of money invested at 10% per year
1.09y-1.1x=$43 - the difference is $43
What the other person posted (see above), makes absolutely NO SENSE!!
Let amount invested at 9%, be N, and amount invested at 10%,T
Then we get the following TOTAL-INVESTMENT equation: N + T = 4.800 ---- eq (i)
In addition, interest EARNED from the 9% investment = .09N, while 10% earned .1T
We then get the following equation for the DIFFERENCE in INTEREST EARNED from each investment: .09N = .1T - 43 ---- eq (ii)
We now have the following system of equations:
N + T = 4.800 ------ eq (i)
T = 4.800 - N -- eq (i)
.09N = .1T - 43 --- eq (ii)
.09N = .1(4,800 - N) - 43 ---- Substituting 4,800 - N for T, in eq (ii)
.09N = 480 - .1N - 43
.09N = 437 - .1N
.09N + .1N = 437
.19N = 437
Amount invested at 9%, or 
Amount invested at 10%: $4,800 - $2,300 = $2,500
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