document.write( "Question 334722: A copper alloy that is 40% copper is to be combined with a copper alloy that is 80% copper to produce 120 kilograms of an alloy that is 70% copper. How many kilograms of each alloy must be used? \n" ); document.write( "
Algebra.Com's Answer #239844 by stanbon(75887)\"\" \"About 
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A copper alloy that is 40% copper is to be combined with a copper alloy that is 80% copper to produce 120 kilograms of an alloy that is 70% copper. How many kilograms of each alloy must be used?
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\n" ); document.write( "Equation:
\n" ); document.write( "copper + copper = copper
\n" ); document.write( "0.40x + 0.80(120-x) = 0.70*120
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\n" ); document.write( "Multiply thru by 100 to get:
\n" ); document.write( "40x + 80*120 - 80x = 70*120
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\n" ); document.write( "-40x = -10*120
\n" ); document.write( "x = (1/4)120
\n" ); document.write( "x = 30 kg (amt. of 40% alloy needed in the mixture.
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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