document.write( "Question 1116363: susan invest 2 times as much money at 9% as she does at 6%. If her total interest after 1 year is $1440, how much does she invest at each rate? \n" ); document.write( "
Algebra.Com's Answer #731247 by ikleyn(52778)\"\" \"About 
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document.write( "Let x be an amount invested at 6% (the lesser amount).\r\n" );
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document.write( "Then the amount invested at 9% is 2x, according to the condition.\r\n" );
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document.write( "Your equation to find x is\r\n" );
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document.write( "interest + interest   = total interest,    or\r\n" );
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document.write( "0.06x    + 0.09*(2x)  = 1440\r\n" );
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document.write( "0.06x + 0.18x = 1440  ====>  0.24x = 1440  ====>  x = \"1440%2F0.24\" = 6000.\r\n" );
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document.write( "Answer.  $6000 was invested at 6%.  $12000 was invested at 9%.\r\n" );
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document.write( "Check.   0.06*6000 + 0.09*12000 = 1440 dollars.   ! Correct !\r\n" );
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\n" ); document.write( "It is a typical and standard problem on investment.\r
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\n" ); document.write( "\n" ); document.write( "To see many other similar solved problems on investment,  look into the lesson\r
\n" ); document.write( "\n" ); document.write( "    - Using systems of equations to solve problems on investment\r
\n" ); document.write( "\n" ); document.write( "in this site.\r
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\n" ); document.write( "\n" ); document.write( "You will find there different approaches  (using one equation or a system of two equations in two unknowns),  as well as
\n" ); document.write( "different methods of solution to the equations  (Substitution,  Elimination).\r
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\n" ); document.write( "\n" ); document.write( "Also,  you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lesson is the part of this online textbook under the topic  \"Systems of two linear equations in two unknowns\".\r
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\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
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