document.write( "Question 144670: turf's grass seed cost 60 cents a pound and lumpy's grass seed cost cost 45 cents a pound. How many pounds of each were used to to make a 40-pound mixture that cost $20.25\r
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\n" ); document.write( "\n" ); document.write( " i'm so confused!! \n" ); document.write( "
Algebra.Com's Answer #105423 by tutorcecilia(2152)\"\" \"About 
You can put this solution on YOUR website!
Use the following formulas:
\n" ); document.write( "x+y= total amount
\n" ); document.write( "ax+by= total cost
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\n" ); document.write( "Plugging in the values:
\n" ); document.write( "x+y=40
\n" ); document.write( "or y = 40-x
\n" ); document.write( "and
\n" ); document.write( ".60x+.45y=20.25
\n" ); document.write( ".
\n" ); document.write( "Substituting y=40-x gives:
\n" ); document.write( ".60x + .45(40-x) = 20.25
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\n" ); document.write( "Solving for the x-value:
\n" ); document.write( ".60x+18-.45x = 20.25
\n" ); document.write( ".60x-.45x=20.25-18
\n" ); document.write( ".15x =2.25
\n" ); document.write( "x=2.25/.15
\n" ); document.write( "x=15lbs at .60 cents/lbs
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\n" ); document.write( "So,
\n" ); document.write( "x+y=40
\n" ); document.write( "15+y=40
\n" ); document.write( "y=40-15
\n" ); document.write( "y=25 lbs at .45 cents/lbs \r
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