document.write( "Question 52688This question is from textbook Intoductory Algebra
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document.write( ": A metallurgist has one alloy cantaining 20% copper and another containing 70% copper. How many pounds of each alloy must he use to make 50 pounds of a third alloy containing 50% copper?
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document.write( "Find the equation(s) and solve. \n" );
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Algebra.Com's Answer #35167 by funmath(2933)![]() ![]() ![]() You can put this solution on YOUR website! Let the amount of 20% copper=x \n" ); document.write( "Then the rest of the mixture would be 70%, let the amount of 70% mixture=50-x \n" ); document.write( "You multiply percent times amount to get the solutions. \n" ); document.write( ".20x+.70(50-x)=.50(50) To eliminate the decimals, multiply both sides of the equation by 100 or 10. \n" ); document.write( "10(.20x)+10(.70)(50-x)=10(.50)(50) \n" ); document.write( "2x+7(50-x)=5(50) \n" ); document.write( "2x+350-7x=250 \n" ); document.write( "-5x+350=250 \n" ); document.write( "-5x+350-350=250-350 \n" ); document.write( "-5x=-100 \n" ); document.write( "-5x/-5=-100/-5 \n" ); document.write( "x=20 \n" ); document.write( "The amount of 20% alloy is 20 pounds. \n" ); document.write( "The amount of 70% alloy is 50-20=30 pounds. \n" ); document.write( " |