document.write( "Question 1134714: Grace has $10,000 to invest. She invests some at 2.5% interest and the rest at 4% interest. How much should she invest at each rate to earn $310 in interest in one year? \n" ); document.write( "
Algebra.Com's Answer #752173 by ikleyn(52777)\"\" \"About 
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document.write( "0.04x + 0.025*(10000-x) = 310   dollars.\r\n" );
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document.write( "x = \"%28310-0.025%2A10000%29%2F%280.04+-+0.025%29\" = 4000 dollars.\r\n" );
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document.write( "Answer.  $4000 invested at 4% and the rest $6000 invested ar 2.5%.\r\n" );
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document.write( "CHECK.   0.04*4000 + 0.025*6000 = 310 dollars.    ! Correct !\r\n" );
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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( "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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