document.write( "Question 281130: This is a weighted average word problem, that i really need the answer to:
\n" ); document.write( "whipping cream contains 9% butter fat. 2% milk contains 2% butterfat.
\n" ); document.write( "How much whipping cream and 2% milk should be mixed to obtain 35 gallons of milk with 4% butterfat?
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Algebra.Com's Answer #204233 by Fombitz(32388)\"\" \"About 
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Let the amount of whipping cream be W and let the amount of 2% milk be T.
\n" ); document.write( "1.\"W%2BT=35\" - Volume equation
\n" ); document.write( "2.\"9W%2B2T=4%2A%28W%2BT%29=4%2835%29=140\" - Concentration equation
\n" ); document.write( "Use eq. 1 to solve for W in terms of T.
\n" ); document.write( "\"W%2BT=35\"
\n" ); document.write( "\"W=35-T\"
\n" ); document.write( "Now substitute into eq. 2 and solve for T.
\n" ); document.write( "\"9W%2B2T=140\"
\n" ); document.write( "\"9%2835-T%29%2B2T=140\"
\n" ); document.write( "\"315-9T%2B2T=140\"
\n" ); document.write( "\"-7T=-175\"
\n" ); document.write( "\"T=25\"
\n" ); document.write( "Then from eq. 1,
\n" ); document.write( "\"W=35-T=35-25=10\"
\n" ); document.write( "10 gallons of whipping cream and 25 gallons of 2% milk.
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