document.write( "Question 869888: A total of $18,000 is invested in two corporate bonds that pay 3.5% and 5% simple interest. The investor wants an annual interest income of $750 from the investments. What amount should be invested in the 3.5% bond? \n" ); document.write( "
Algebra.Com's Answer #524611 by mananth(16946)\"\" \"About 
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Part I 3.50% per annum ------------- Amount invested =x
\n" ); document.write( "Part II 5.00% per annum ------------ Amount invested = y
\n" ); document.write( " 18000
\n" ); document.write( "Interest----- 750.00
\n" ); document.write( "
\n" ); document.write( "Part I 3.50% per annum ---x
\n" ); document.write( "Part II 5.00% per annum ---y
\n" ); document.write( "Total investment
\n" ); document.write( "x + 1 y= 18000 -------------1
\n" ); document.write( "Interest on both investments
\n" ); document.write( "3.50% x + 5.00% y= 750
\n" ); document.write( "Multiply by 100
\n" ); document.write( "3.5 x + 5 y= 75000.00 --------2
\n" ); document.write( "Multiply (1) by -3.5
\n" ); document.write( "we get
\n" ); document.write( "-3.5 x -3.5 y= -63000.00
\n" ); document.write( "Add this to (2)
\n" ); document.write( "0 x 1.5 y= 12000
\n" ); document.write( "divide by 1.5
\n" ); document.write( " y = 8000
\n" ); document.write( "Part I 3.50% $ 10000
\n" ); document.write( "Part II 5.00% $ 8000
\n" ); document.write( "
\n" ); document.write( "CHECK
\n" ); document.write( "10000 --------- 3.50% ------- 350.00
\n" ); document.write( "8000 ------------- 5.00% ------- 400.00
\n" ); document.write( "Total -------------------- 750.00
\n" ); document.write( "
\n" ); document.write( "m.ananth@hotmail.ca
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