document.write( "Question 499343: The manager of a coffee shop has one type of coffee that sells for $6 per pound and another type that sells for $13 per pound. The manager wishes to mix 30 pounds of the $13 coffee to get a mixture that will sell for $9 per pound. How many pounds of the $6 coffee should be used? \n" ); document.write( "
Algebra.Com's Answer #337598 by oberobic(2304)\"\" \"About 
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x = lb of one coffee
\n" ); document.write( "13x = value of that coffee
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\n" ); document.write( "30-x = lb of other coffee
\n" ); document.write( "6(30-x) = value of that coffee
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\n" ); document.write( "30 = lb of coffee in final mix
\n" ); document.write( "9(30) = 270 = value of the final mix
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\n" ); document.write( "13x + 6(30-x) = 270
\n" ); document.write( "13x + 180 -6x = 270
\n" ); document.write( "7x = 90
\n" ); document.write( "x = 90/7 lb
\n" ); document.write( "x = 12 6/7 lb of the more expensive coffee
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\n" ); document.write( "That means you will add
\n" ); document.write( "30-x = 17 1/7 lb of the cheaper coffee
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