document.write( "Question 1203605: If an amount of $9,000 is invested at a simple interest rate of
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Algebra.Com's Answer #839283 by ikleyn(52781) $\"\"$ $\"About$

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If an amount of $9,000 is invested at a simple interest rate of 3 1/2% interest per year,
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document.write( "Let x be the value under the problem question (= an additional amount to invest at 5%).\r\n" );
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document.write( "From one side, these two amounts of $9000 and x dollars generate the total annual interest\r\n" );
document.write( "of 0.035*19000 + 0.05x  dollars.\r\n" );
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document.write( "From the other side, we want to have the total annual interest of 0.04(9000+x)  dollars.\r\n" );
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document.write( "So, we write this equation\r\n" );
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document.write( "    0.035*9000 + 0.05x = 0.04(9000+x)   dollars.\r\n" );
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document.write( "Now simplify and find x\r\n" );
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document.write( "    0.035*9000 + 0.05x = 0.04*9000 + 0.04x\r\n" );
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document.write( "    0.05x - 0.04x = 0.04*9000 - 0.035*9000\r\n" );
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document.write( "        0.01x     =       45\r\n" );
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document.write( "            x     =       45/0.01 = 4500.\r\n" );
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document.write( "ANSWER.  An additional amount to invest at 5% is 4500 dollars.\r\n" );
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