document.write( "Question 607390: $10,000 is to be invested in three different ways. One part of the money is used to purchase mutual fund that offer a return of 8% per year. The second part, which amounts to twice the first, is used to buy government bonds at 9% per year. The remainder is put in the bank at 5% annual interest. In the first year, the investments bring a return of $830. How much was invested in each way?\r
\n" ); document.write( "\n" ); document.write( "This is a matrices problem but I am confused with how to begin with the equations.
\n" ); document.write( "Is one equation x + y + z = 10,000? The second equation.. Is is something like this? 0.08x + 2(0.09)y = \r
\n" ); document.write( "\n" ); document.write( "I will be able to solve the problem after understanding how to put the wording into equations.. I understand how to solve matrices, so I am not asking for help with that. Thank you.
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Algebra.Com's Answer #382787 by ankor@dixie-net.com(22740)\"\" \"About 
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$10,000 is to be invested in three different ways.
\n" ); document.write( " One part of the money is used to purchase mutual fund that offer a return of 8% per year.
\n" ); document.write( "The second part, which amounts to twice the first, is used to buy government bonds at 9% per year.
\n" ); document.write( " The remainder is put in the bank at 5% annual interest.
\n" ); document.write( " In the first year, the investments bring a return of $830.
\n" ); document.write( " How much was invested in each way?
\n" ); document.write( ":
\n" ); document.write( "Let x = amt invested at 8%
\n" ); document.write( "Let y = amt invested at 9%
\n" ); document.write( "Let z = amt invested at 5%
\n" ); document.write( ":
\n" ); document.write( "\"$10,000 is to be invested in three different ways.\"
\n" ); document.write( "x + y + z = 10000
\n" ); document.write( ":
\n" ); document.write( "\"One part of the money is used to purchase mutual fund that offer a return of 8% per year. The second part, which amounts to twice the first, is used to buy government bonds at 9% per year.\"
\n" ); document.write( "y = 2x
\n" ); document.write( "-2x + y = 0
\n" ); document.write( ":
\n" ); document.write( "\" the first year, the investments bring a return of $830.
\n" ); document.write( ".08x + .09y + .05z = 830
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\n" ); document.write( "From these three equations we can derive a matrix
\n" ); document.write( " 1, 1, 1, 10000
\n" ); document.write( "-2, 1, 0, 0
\n" ); document.write( ".08, .09, .05, 830\r
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\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " How much was invested in each way?
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