document.write( "Question 550493: A mother wants to invest $6,000.00 for her son's future education. She invests a portion of the money in a bank certificate of deposit which earns 4% interest and the remainder in a savings bond that earns 7%. If the total interest earned after one year is $360.00, how much money was invested into the Certificate of Deposit account? \n" ); document.write( "

Algebra.Com's Answer #358875 by mananth(16946) $\"\"$ $\"About$

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Investment I 4.00% per annum
\n" ); document.write( "Investment II 7.00% per annum
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\n" ); document.write( "x+y 6000 ------------------------1
\n" ); document.write( "4.00%x+7.00% y=$360.00
\n" ); document.write( "Multiply by 100
\n" ); document.write( "4x+7y=$36,000.00 --------2
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\n" ); document.write( "Multiply (1) by -4
\n" ); document.write( "we get
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\n" ); document.write( "-4x-4y= -24000.00
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\n" ); document.write( "Add this to (2)
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\n" ); document.write( "3y = $12,000.00
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\n" ); document.write( "divide by 3
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\n" ); document.write( "y = $4,000.00 investment at 7.00%
\n" ); document.write( "Balance $2,000.00 investment at 4.00%
\n" ); document.write( "CHECK
\n" ); document.write( "$2,000.00 $80.00
\n" ); document.write( "$4,000.00 $280.00
\n" ); document.write( "Total $360.00
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