document.write( "Question 805514: A woman invested some money at 8% and some at 9% annual simple interest. The interest for 1 year on the combined investment of $10,000 was $830. How much was invested at each rate? \n" ); document.write( "

Algebra.Com's Answer #485287 by mananth(16946) $\"\"$ $\"About$

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Part I 8.00% per annum ------------- Amount invested =x
\n" ); document.write( "Part II 9.00% per annum ------------ Amount invested = y
\n" ); document.write( " 10000
\n" ); document.write( "Interest----- 830.00
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\n" ); document.write( "Part I 8.00% per annum ---x
\n" ); document.write( "Part II 9.00% per annum ---y
\n" ); document.write( "Total investment
\n" ); document.write( "x + 1 y= 10000 -------------1
\n" ); document.write( "Interest on both investments
\n" ); document.write( "8.00% x + 9.00% y= 830
\n" ); document.write( "Multiply by 100
\n" ); document.write( "8 x + 9 y= 83000.00 --------2
\n" ); document.write( "Multiply (1) by -8
\n" ); document.write( "we get
\n" ); document.write( "-8 x -8 y= -80000.00
\n" ); document.write( "Add this to (2)
\n" ); document.write( "0 x 1 y= 3000
\n" ); document.write( "divide by 1
\n" ); document.write( " y = 3000 -
\n" ); document.write( "Part I 8.00% $ 7000
\n" ); document.write( "Part II 9.00% $ 3000
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\n" ); document.write( "CHECK
\n" ); document.write( "7000 --------- 8.00% ------- 560.00
\n" ); document.write( "3000 ------------- 9.00% ------- 270.00
\n" ); document.write( "Total -------------------- 830.00
\n" ); document.write( "
\n" ); document.write( "m.ananth@hotmail.ca
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