document.write( "Question 1196056: Walt made an extra $10,000 last year from a part-time job. He invested part of the money at 4% and the rest at 3%. He made a total of $370 in interest. How much was invested at 3%? \n" ); document.write( "

Algebra.Com's Answer #828745 by ikleyn(52794) $\"\"$ $\"About$

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\n" ); document.write( "Walt made an extra $10,000 last year from a part-time job.
\n" ); document.write( "He invested part of the money at 4% and the rest at 3%.
\n" ); document.write( "He made a total of $370 in interest. How much was invested at 3%?
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document.write( "Let x be the amount (in dollars) invested at 3%.\r\n" );
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document.write( "Then the amount invested at 4% is (10,000-x) dollars (the rest).\r\n" );
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document.write( "Having it, write the money equation for the combined interest\r\n" );
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document.write( "    0.03x + 0.04*(10000-x) = 370  dollars.\r\n" );
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document.write( "Simplify and find x\r\n" );
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document.write( "    0.03x + 400 - 0.04x = 370\r\n" );
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document.write( "    0.03x - 0.04x = 370 - 400\r\n" );
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document.write( "       -0.01x     =    -30\r\n" );
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document.write( "            x     =  = 3000.\r\n" );
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document.write( "ANSWER.  $3000 was invested at 3%.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved.\r
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\n" ); document.write( "\n" ); document.write( "It is a standard and typical problem on investments.\r
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\n" ); document.write( "\n" ); document.write( "If you need more details, or if you want to see other similar problems solved by different methods, 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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