document.write( "Question 1144529: A copper alloy that is 35% copper is to be combined with an ally that is 75% copper. The result will be
\n" ); document.write( "750 kg of an alloy that is 60% copper. How many kg of each alloy should be used? \n" ); document.write( "

Algebra.Com's Answer #765675 by ikleyn(52802) $\"\"$ $\"About$

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document.write( "Let x be the amount of the 75%  copper alloy needed (in kilograms), and\r\n" );
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document.write( "let y be the amount of the 35%  copper alloy needed.\r\n" );
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document.write( "The mass of the copper in the 75% alloy is 0.75x kilograms.\r\n" );
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document.write( "The mass of the copper in the 35% alloy is 0.35y kilograms.\r\n" );
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document.write( "The resulting alloy contains  0.75x + 0.35y kilograms of the copper and has the mass of 750 kilograms.\r\n" );
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document.write( "Thus you have these two equations\r\n" );
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document.write( "    x + y = 750    kilograms             (1)    (the total mass)\r\n" );
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document.write( "     = 0.60.                 (2)    (the resulting alloy concentration of copper)\r\n" );
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document.write( "From equation  (1), express  y = 750 - x.  Substitute it into equation (2) and multiply both sides of this equation by 750. \r\n" );
document.write( "You will get\r\n" );
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document.write( "    0.75*x + 0.35*(750-x) = 0.60*750.\r\n" );
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document.write( "From the last equation express x and calculate\r\n" );
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document.write( "    x =  = 468.75 kilograms of the 75% copper alloy are needed.\r\n" );
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document.write( "Then from equation (1),  y = 750 - 468.75 = 281.25 kilograms of the 35% copper alloy are needed.\r\n" );
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document.write( "Answer. 468.75 kilograms of the 75% alloy  and  281.25 kilograms of the 35% alloy are  needed.\r\n" );
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document.write( "Check.   = 0.6 = 60%.   ! Correct concentration !\r\n" );
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\n" ); document.write( "\n" ); document.write( "The problem is just solved.\r
\n" ); document.write( "\n" ); document.write( "I used 2-equation setup and the Substitution method.\r
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\n" ); document.write( "\n" ); document.write( "There are other solution methods, too.\r
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\n" ); document.write( "\n" ); document.write( "--------------\r
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\n" ); document.write( "\n" ); document.write( "There is entire bunch of introductory lessons covering various types of mixture problems\r
\n" ); document.write( "\n" ); document.write( "    - Mixture problems\r
\n" ); document.write( "\n" ); document.write( "    - More Mixture problems\r
\n" ); document.write( "\n" ); document.write( "    - Solving typical word problems on mixtures for solutions \r
\n" ); document.write( "\n" ); document.write( "    - Word problems on mixtures for antifreeze solutions \r
\n" ); document.write( "\n" ); document.write( "    - Word problems on mixtures for alloys (*)\r
\n" ); document.write( "\n" ); document.write( "    - Typical word problems on mixtures from the archive\r
\n" ); document.write( "\n" ); document.write( "    - Advanced mixture problems \r
\n" ); document.write( "\n" ); document.write( "    - Advanced mixture problem for three alloys \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 ALL TYPICAL mixture problems with different methods of solutions,
\n" ); document.write( "explained at different levels of detalization, from very detailed to very short.\r
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\n" ); document.write( "\n" ); document.write( "Read them and become an expert in solution mixture word problems.\r
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\n" ); document.write( "\n" ); document.write( "The most relevant to your problem is the lesson marked (*) in the list.\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 lessons are the part of this textbook in the section \"Word problems\" under the topic \"Mixture problems\".\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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