document.write( "Question 509620: Walt made an extra $10,000 last year from a part-time job. He invested part of the money at 8% and the rest at 6%. He made a total of $720 in interest. How much was invested at 6%? \n" ); document.write( "

Algebra.Com's Answer #341517 by mananth(16946) $\"\"$ $\"About$

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Investment II 8.00% per annum ---x
\n" ); document.write( "Investment II 7.00% per annum ---y
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\n" ); document.write( "x+y= 10000 ------------------------1
\n" ); document.write( "8.00% x + 7.00% y = $720.00
\n" ); document.write( "Multiply by 100
\n" ); document.write( "8 x + 7 y = $72,000.00 --------2
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\n" ); document.write( "Multiply (1) by -8
\n" ); document.write( "we get
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\n" ); document.write( "-8x-8y =-80000.00
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\n" ); document.write( "Add this to (2)
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\n" ); document.write( "0 x -1 y = -$8,000.00
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\n" ); document.write( "divide by -1
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\n" ); document.write( "y = $8,000.00 investment at 7.00%
\n" ); document.write( "Balance $2,000.00 investment at 8.00%
\n" ); document.write( "CHECK
\n" ); document.write( "$2,000.00 --------- 8.00% ------- $160.00
\n" ); document.write( "$8,000.00 ------- 7.00% ------- $560.00
\n" ); document.write( "Total ------- $720.00
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