document.write( "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:
\n" ); document.write( "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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Algebra.Com's Answer #853701 by MathTherapy(10806) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "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 \r\n" );
document.write( "substitution but the only problem I have is finding the equations within the problem. Thanks so much in advance! Here is the question: \r\n" );
document.write( "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?\r\n" );
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document.write( "Post from the other person:\r\n" );
document.write( "1.09y - part of the money invested at 9% per year\r\n" );
document.write( "1.1x - part of money invested at 10% per year\r\n" );
document.write( "1.09y-1.1x=$43 - the difference is $43\r\n" );
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document.write( "What the other person posted (see above), makes absolutely NO SENSE!! \r\n" );
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document.write( "Let amount invested at 9%, be N, and amount invested at 10%,T\r\n" );
document.write( "Then we get the following TOTAL-INVESTMENT equation: N + T = 4.800 ---- eq (i)\r\n" );
document.write( "In addition, interest EARNED from the 9% investment = .09N, while 10% earned .1T\r\n" );
document.write( "We then get the following equation for the DIFFERENCE in INTEREST EARNED from each investment: .09N = .1T - 43 ---- eq (ii)\r\n" );
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document.write( "We now have the following system of equations:\r\n" );
document.write( "     N + T = 4.800 ------ eq (i)\r\n" );
document.write( "         T = 4.800 - N -- eq (i)\r\n" );
document.write( "      .09N = .1T - 43 --- eq (ii) \r\n" );
document.write( "      .09N = .1(4,800 - N) - 43 ---- Substituting 4,800 - N for T, in eq (ii)\r\n" );
document.write( "      .09N = 480 - .1N - 43\r\n" );
document.write( "      .09N = 437 - .1N\r\n" );
document.write( ".09N + .1N = 437\r\n" );
document.write( "      .19N = 437\r\n" );
document.write( "Amount invested at 9%, or \r\n" );
document.write( "Amount invested at 10%: $4,800 - $2,300 = $2,500

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