document.write( "Question 1140269: Sam invested $2000, part of it at 6% and the rest at 8% yearly interest. The yearly income on the 8% investment was $20 more than twice the income from the 6% investment. How much did he invest at each rate? \n" ); document.write( "

Algebra.Com's Answer #760744 by ikleyn(52786) $\"\"$ $\"About$

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document.write( "Let x = amount at 8%, in dollars.\r\n" );
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document.write( "Then the amount at 6% is the rest (2000-x) dollars.\r\n" );
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document.write( "The interest from the 8% amount is 0.08*x  dollars.\r\n" );
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document.write( "The interest from the 6%   amount is 0.06*(2000-x)   dollars.\r\n" );
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document.write( "Your equation is\r\n" );
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document.write( "    interest at 8% - 2*(interest at 6%)   = 20  dollars,   or\r\n" );
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document.write( "    0.08*x         - 2*0.06*(2000-x)      = 20  dollars.\r\n" );
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document.write( "Simplify this equation, express x and calculate the answer\r\n" );
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document.write( "    0.08x - 2*0.06*2000 + 0.12x = 20,\r\n" );
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document.write( "    x =  = 1300.\r\n" );
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document.write( "Answer.  The amount at 8% is $1300;  the rest  $2000-$1300 = $700 is the amount at 6%.\r\n" );
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document.write( "Check.   0.08*1300 - 2*0.06*700 = 20 dollars.   ! Correct !\r\n" );
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\n" ); document.write( "\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( "\n" ); document.write( "Save the link to this online textbook together with its description\r
\n" ); document.write( "
\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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